feat(laya): port the language/script detector that picks the checkpoint (#339)

Laya ships an English checkpoint and a multilingual one, and the
English one is confidently wrong outside English (0.000 accuracy at
0.952 confidence on Khmer). The SDK routes between them with
`laya.lang.analyse`; this is that function in Rust, rule for rule:
script counts over letters, a function-word vote with margins for
Latin-script text, a diacritic fallback for Latin languages with no
word list, the English rescue for loanwords, and the line-by-line and
field-by-field rescan that stops a long English part outvoting a short
foreign message. `Analysis` serialises to the same JSON the SDK's
`routing.detection` block carries.

The heuristics sit on Python's Unicode semantics, and each place Rust's
defaults differ is replicated explicitly (documented in the module):
`isalpha` is General_Category L* (not Alphabetic, which admits marks),
`re`'s word class excludes combining marks, `str.split` treats
U+001C..U+001F as whitespace, `unicodedata.combining` is the canonical
combining class, `str.isupper` is "no lowercase or titlecase, at least
one uppercase", and budgets count code points. The identifier regex
uses a lookbehind the regex crate lacks and is a hand-written scanner.
Tables (script ranges, word lists, diacritics) were generated from the
SDK source, not retyped.

Parity: script/laya-lang-reference.py records the SDK over 924 cases
(every script range, each word-list language accented and
ASCII-stripped, code and identifiers, multi-line and structured
states, the 4000-character budgets and depth limit, Unicode edge cases,
and a seeded fuzz), all matching exactly. Mutation-checked: every
behaviour-changing mutation of the Unicode handling and of the rules
above fails at least one case. The one surviving mutant, half-away
rounding of the non-Latin letter count, is equivalent: the two
rounding rules only disagree on ties that land on the same side of the
10-letter threshold.

Caveat for callers: an object state's value order decides what is read
first. Python keeps insertion order; serde_json without
`preserve_order` iterates keys sorted, so multi-field states can differ
from the SDK until the request JSON keeps order. The corpus uses
sorted keys so it tests the detector, not the JSON reader.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VtaCXFAY23HmwX5Cyc6jhC

Cargo.lock

@@ -3166,6 +3166,8 @@ dependencies = [
  "toml",
  "tracing",
  "tracing-subscriber",
+ "unicode-normalization",
+ "unicode-properties",
 ]
 
 [[package]]

crates/neuron/Cargo.toml

@@ -76,6 +76,12 @@ toml.workspace = true
 # transitively via candle-core.
 rayon = "1"
 
+# Unicode tables for the decision-model language detector (#339), which
+# must classify characters exactly as Python's `str.isalpha` / `re` and
+# `unicodedata.combining` do. Both already in the tree via tokenizers.
+unicode-normalization = "0.1"
+unicode-properties = "0.1"
+
 # candle for in-process inference. CUDA support is gated behind the
 # crate's `cuda` feature (default off) so the workspace builds on
 # non-CUDA hosts and CI runners.

crates/neuron/src/harness/mod.rs

@@ -10,6 +10,7 @@ pub mod device_worker;
 pub mod engine;
 pub mod image;
 pub mod isq_cache;
+pub mod lang_detect;
 pub mod prefix_cache;
 pub mod preflight;
 pub mod preprocess;

script/laya-lang-reference.py

@@ -0,0 +1,361 @@
+#!/usr/bin/env python3
+"""Record Laya's language/script detector over a broad corpus (#339).
+
+neuron routes each decision request to the English or multilingual Laya
+checkpoint with a port of `laya.lang.analyse`. That function is a pile of
+heuristics sitting on Python's Unicode semantics -- `str.isalpha`, `re`'s
+`\\w`, `unicodedata.combining`, `str.lower`, `str.split` -- and a port that
+reads the same can still route differently. This records the reference's
+answer over a corpus built to reach every rule and every place those
+semantics could diverge:
+
+  - every script range, real sentences and generated letter runs
+  - each function-word language, accented and ASCII-stripped, long and short
+  - English with loanwords, names, symbols and IPA; code, URLs, e-mails,
+    identifiers, acronyms and slash compounds
+  - mixed-script and mixed-language states, multi-line and structured
+  - the 4000-character budgets, the nesting depth limit, non-string leaves
+  - combining marks, decomposed text, case-mapping oddities (İ, ß, final
+    sigma, titlecase digraphs), fullwidth forms, numerals, emoji, and the
+    whitespace Python and Rust disagree about
+  - a seeded fuzz section mixing all of the above
+
+Every mapping in the corpus has its keys in sorted order, so a consumer
+whose JSON maps iterate in key order (serde_json without `preserve_order`)
+sees the same leaf order Python does.
+
+Characters are limited to those assigned in the Unicode version of the
+Python that records the corpus, so a newer Unicode table on the consuming
+side cannot disagree about a code point Python considers unassigned.
+
+Usage (any Python 3.10+ with the laya SDK importable; no model, no network):
+
+    python script/laya-lang-reference.py \\
+        --out crates/neuron/src/harness/testdata/laya/lang_corpus.json
+"""
+import argparse
+import json
+import random
+import sys
+import unicodedata
+
+import laya
+from laya.lang import _WORD, _iter_text, analyse
+
+SENTENCES = {
+    "en": "Please refund the duplicate charge, I was billed twice this month and it is not fair.",
+    "en_short": "refund please",
+    "en_loanword": "I would like a café table and my résumé is attached for the role.",
+    "en_name": "José and Zoë have the tickets that were sent to you from the office.",
+    "en_two_loanwords": "The naïve café owner sent the résumé to you and it was not what we wanted.",
+    "en_symbols": "Set α to 0.05 and β to 0.9, then run the job again with the new values.",
+    "en_russian_name": "The report from Дмитрий Петрович Савицкий was sent to the team yesterday.",
+    "en_ipa": "Vladimir is pronounced [vlɐˈdʲimʲɪr] in Russian and that is how we say it.",
+    "en_stress": "The name Влади́мир has a stress mark on the second syllable for you.",
+    "fr": "Bonjour, je voudrais annuler ma commande car elle est arrivée très en retard.",
+    "fr_short": "merci beaucoup",
+    "de": "Die Rechnung ist falsch, bitte korrigieren Sie den Betrag für diesen Monat.",
+    "de_short": "Danke schön",
+    "de_eszett": "Ich möchte die Straße und die Größe meiner Bestellung ändern, bitte.",
+    "es": "Me han cobrado dos veces este mes y quiero que me devuelvan el dinero ya.",
+    "pt": "Não consigo acessar a minha conta, já tentei redefinir a senha várias vezes.",
+    "pt_br": "Voce pode me mandar a nota fiscal? Nao recebi nada ate agora.",
+    "pt_ticket": "Deu erro 500 no endpoint de login depois do update de ontem.",
+    "it": "Vorrei sapere quando arriverà il mio ordine, è già in ritardo di una settimana.",
+    "nl": "Het pakket is niet aangekomen en ik wil graag een terugbetaling voor deze bestelling.",
+    "ro": "Vreau să anulez comanda pentru că produsul este deteriorat și nu funcționează.",
+    "bn": "ami taka ferot chai, amar order ekhono ashe nai, ki korbo bolun",
+    "az": "Mən sifarişi ləğv etmək istəyirəm, çünki məhsul çox gec gəldi.",
+    "tr": "Siparişimi iptal etmek istiyorum çünkü ürün çok geç geldi ve kırık.",
+    "pl": "Chciałbym zwrócić pieniądze, ponieważ paczka dotarła uszkodzona.",
+    "cs": "Chtěl bych vrátit peníze, protože zásilka dorazila poškozená.",
+    "hu": "Szeretném visszakapni a pénzemet, mert a csomag sérülten érkezett.",
+    "vi": "Tôi muốn được hoàn tiền vì gói hàng đã đến bị hư hỏng.",
+    "sv": "Jag vill ha pengarna tillbaka eftersom paketet kom fram skadat.",
+    "da": "Jeg vil gerne have pengene tilbage, fordi pakken kom i stykker.",
+    "sw": "Nataka kurudishiwa pesa zangu kwa sababu kifurushi kiliharibika.",
+    "la_shared_only": "la la e e o o un un",
+    "el": "Θέλω να ακυρώσω την παραγγελία μου γιατί ήρθε πολύ αργά.",
+    "el_upper_sigma": "ΘΕΛΩ ΤΗΝ ΕΠΙΣΤΡΟΦΗ ΧΡΗΜΑΤΩΝ ΤΟΥ ΛΟΓΑΡΙΑΣΜΟΥ ΣΑΣ",
+    "ru": "Мне дважды списали деньги в этом месяце, верните, пожалуйста.",
+    "uk": "Мені двічі списали гроші цього місяця, поверніть, будь ласка.",
+    "hy": "Ես ուզում եմ չեղարկել պատվերս, քանի որ այն ուշ հասավ։",
+    "he": "אני רוצה לבטל את ההזמנה שלי כי היא הגיעה באיחור.",
+    "he_niqqud": "שָׁלוֹם, אֲנִי רוֹצֶה לְבַטֵּל אֶת הַהַזְמָנָה",
+    "ar": "تم خصم المبلغ مرتين هذا الشهر، أريد استرداد أموالي من فضلكم.",
+    "fa": "می‌خواهم سفارشم را لغو کنم چون خیلی دیر رسید.",
+    "hi": "मुझे इस महीने दो बार शुल्क लिया गया, मुझे पैसे वापस चाहिए।",
+    "bn_script": "এই মাসে আমার কাছ থেকে দুবার টাকা কাটা হয়েছে, টাকা ফেরত চাই।",
+    "pa": "ਮੈਨੂੰ ਇਸ ਮਹੀਨੇ ਦੋ ਵਾਰ ਚਾਰਜ ਕੀਤਾ ਗਿਆ, ਪੈਸੇ ਵਾਪਸ ਚਾਹੀਦੇ ਹਨ।",
+    "gu": "મને આ મહિને બે વાર ચાર્જ કરવામાં આવ્યો, પૈસા પાછા જોઈએ છે.",
+    "or": "ମୋତେ ଏହି ମାସରେ ଦୁଇଥର ଚାର୍ଜ କରାଯାଇଛି।",
+    "ta": "இந்த மாதம் எனக்கு இரண்டு முறை கட்டணம் வசூலிக்கப்பட்டது.",
+    "te": "ఈ నెలలో నాకు రెండుసార్లు ఛార్జ్ చేశారు, డబ్బు తిరిగి ఇవ్వండి.",
+    "kn": "ಈ ತಿಂಗಳು ನನಗೆ ಎರಡು ಬಾರಿ ಶುಲ್ಕ ವಿಧಿಸಲಾಗಿದೆ.",
+    "ml": "ഈ മാസം എനിക്ക് രണ്ടുതവണ ചാർജ് ഈടാക്കി.",
+    "si": "මෙම මාසයේ මට දෙවරක් ගාස්තු අය කළා.",
+    "th": "เดือนนี้ฉันถูกเรียกเก็บเงินสองครั้ง ขอเงินคืนด้วยค่ะ",
+    "lo": "ເດືອນນີ້ຂ້ອຍຖືກເກັບເງິນສອງເທື່ອ",
+    "bo": "ང་ལ་ཟླ་བ་འདིར་ཐེངས་གཉིས་རིན་བསྡུས་སོང་།",
+    "my": "ဒီလမှာ ကျွန်တော့်ကို နှစ်ကြိမ် ငွေတောင်းခံခဲ့တယ်။",
+    "ka": "ამ თვეში ორჯერ ჩამომეჭრა თანხა, გთხოვთ დამიბრუნოთ.",
+    "am": "በዚህ ወር ሁለት ጊዜ ክፍያ ተቀንሶብኛል፣ እባክዎ ይመልሱልኝ።",
+    "km": "ខ្ញុំត្រូវបានគិតប្រាក់ពីរដងក្នុងខែនេះ ខ្ញុំចង់បានប្រាក់វិញ",
+    "ko": "이번 달에 두 번 청구되었습니다. 환불해 주세요.",
+    "ja": "今月二回請求されました。返金をお願いします。",
+    "ja_kana": "ありがとうございます。キャンセルしたいです。",
+    "zh": "这个月我被扣了两次钱，我要退款，请尽快处理。",
+    "zh_trad": "這個月我被扣了兩次錢，我要退款。",
+    "yue_ext_b": "𠮷野家の𩸽を食べたい",
+    "mn_cyr": "Би захиалгаа цуцлахыг хүсч байна.",
+    "bopomofo": "ㄅㄆㄇㄈ ㄉㄊㄋㄌ",
+    "halfwidth_kana": "ｷｬﾝｾﾙｼﾀｲﾃﾞｽ",
+    "cherokee": "ᏣᎳᎩ ᎦᏬᏂᎯᏍᏗ",
+}
+
+EXTRA = [
+    "", " ", "   \n\t  ", "12345 67890", "3.14 2.71 1.41", "!!! ??? ...", "ok", "a", "no",
+    "🙂🙂🙂 👍", "refund 🙂 please 👍 thanks", "café", "résumé naïve café",
+    "ß", "Straße", "İstanbul İzmir", "ıi İI", "Džemal Ljubljana Nj", "ⓐⓑⓒ ⒶⒷⒸ", "𝐀𝐁𝐂 𝐚𝐛𝐜 test",
+    "Ⅰ Ⅱ Ⅲ ⅳ ⅴ", "x² y³ ½ ¾", "٣٤٥ ١٢", "१२३ ४५६", "ＦＵＬＬＷＩＤＴＨ ｔｅｘｔ ｈｅｒｅ",
+    "ʰʲʷ ˈˌ", "ɐɑɒ ʃʒ θð", "ƀƁƂ ǝǞ ȀȁȂ", "Ȿ ɀ", "ḀḁḂḃ ẞ ỳỹ",
+    "a\x1cb\x1dc\x1ed\x1ff", "word\u00a0word\u00a0word\u00a0word", "一\u3000二\u3000三",
+    "tab\tseparated\tvalues\there", "zero\u200bwidth\u200bjoiner", "soft\u00adhyphen",
+    "e\u0301 e\u0300 a\u0308 o\u0303", "Tôi muốn được hoàn tiền",
+    unicodedata.normalize("NFD", "Tôi muốn được hoàn tiền vì gói hàng đã đến bị hư hỏng."),
+    unicodedata.normalize("NFD", "Não consigo acessar a minha conta, já tentei várias vezes."),
+    unicodedata.normalize("NFD", "Vreau să anulez comanda pentru că produsul este deteriorat."),
+    "ΟΔΟΣ ΟΔΟΣ ΟΔΟΣ", "Σ", "ΑΣ ΑΣ", "ὈΔΥΣΣΕΎΣ",
+]
+
+CODE_AND_IDENTIFIERS = [
+    "see https://github.com/acme/os.path and user@acme.com for details",
+    "email me at joao.silva@empresa.com.br or maria@exemplo.pt please",
+    "version v1.2.3 of the lib, see U.S.A. rules and e.g. the docs",
+    "x = round(el, 2); return non_english",
+    "import os.path\nfrom foo import bar",
+    "def f(x):\n    return {'la': 1, 'le': 2}",
+    "Nav/Com OS/2 C:\\DOS\\mode ESA/UN are names not sentences at all",
+    "MON LA EST COM DES are teams, states and radio bands in the listing",
+    "COM COM COM COM radio listing for the English region",
+    "O CLIENTE ESTÁ MUITO IRRITADO COM O ATRASO DO PEDIDO",
+    "call foo(bar) then baz(qux) and see what the output of the call is",
+    "Deu erro (500) no login depois do update de ontem",
+    "a.b.c.d e@f g.h-i j_k.l m-n.o",
+    "-leading.dash and trailing.dot. and @handle and .hidden files here",
+    "..... @@@@ .@. a.@b",
+    "x" * 300 + ".com",
+    "path/to/file.py line 42 in <module> raise ValueError('não funciona')",
+]
+
+MULTILINE = [
+    "Hello team,\nPlease see below.\nNão consigo acessar a minha conta, já tentei redefinir a senha.\nThanks",
+    "Traceback (most recent call last):\n  File \"app.py\", line 3, in <module>\n    x = foo()\nO sistema não "
+    "está funcionando desde ontem e preciso de ajuda urgente com isso",
+    "Line one in English is here.\nLa fattura è sbagliata, per favore correggetela subito.",
+    "Short line\n\n\nAnother short\nDie Rechnung ist falsch und ich bitte um eine Korrektur heute.",
+    "English only line one.\nEnglish only line two.\nAnd the third line of English text.",
+    "José\nMaría\nFrançois\nplease refund the order that was sent to them",
+    "Ticket #1\nこんにちは、注文をキャンセルしたいです\nThanks for the help with this",
+    # Targeted: each of the next cases flips if one rule is ported wrong.
+    # All-caps function words in mixed-case text are acronyms, not French.
+    "Please refund the duplicate charge, I was billed twice this month and it is not fair.\n"
+    "Scores: MON LA EST DES COM LES ET tonight",
+    # U+001C splits tokens for str.split(), so the identifier is dropped
+    # alone rather than taking the Portuguese words with it.
+    "Please refund the duplicate charge, I was billed twice this month.\n"
+    "Não\x1cconsigo\x1cacessar\x1cminha\x1cconta\x1cjá\x1cx.y",
+    # A combining stress mark must not split a capitalised name into a
+    # lowercase "word".
+    "The customer name on the invoice is Влади́мир "
+    "Петро́вич and we need it fixed today",
+    # One loanword: English function words rescue the marginal diacritic rate.
+    "We will meet at the café for you",
+    "I think the naïve plan is fine for all of us here",
+]
+
+
+def budget_cases():
+    en = "Please refund the duplicate charge on my card for this month. "
+    pt = "Não consigo acessar a minha conta, já tentei redefinir a senha várias vezes. "
+    out = []
+    for n in (3990, 3999, 4000, 4001, 4010, 8000):
+        out.append((en * (n // len(en) + 1))[:n])
+    out.append((en * 70)[:3995] + " " + pt)
+    out.append((en * 70) + pt)
+    out.append((en * 100) + "\n" + pt)
+    out.append("x" * 3999 + "\n" + pt)
+    out.append("x" * 4000 + "\n" + pt)
+    out.append(("é" * 5000))
+    out.append(("ab " * 1400) + pt)
+    return out
+
+
+def structured_cases():
+    en = SENTENCES["en"]
+    pt = SENTENCES["pt"]
+    de = SENTENCES["de"]
+    ja = SENTENCES["ja"]
+    deep = "Não consigo acessar a minha conta, já tentei redefinir a senha."
+    nested = deep
+    deeps = []
+    for depth in range(9):
+        nested = [nested]
+        deeps.append(nested)
+    return [
+        {"body": pt, "subject": "Refund request"},
+        {"body": en, "note": pt},
+        {"a_note": en * 60, "b_message": de},
+        {"a_note": en * 60, "b_message": "Hallo, bitte."},
+        {"customer": "José", "message": en},
+        {"name": "Дмитрий Петрович", "text": en},
+        {"message": ja, "subject": "Order"},
+        {"count": 3, "flag": True, "missing": None, "text": en},
+        {"count": 3, "flag": False, "text": pt},
+        {"items": [en, pt, {"deep": de}], "meta": {"lang": "?"}},
+        {"conversation": [{"content": en, "role": "user"}, {"content": pt, "role": "user"}]},
+        {"a": {"b": {"c": {"d": {"e": {"f": {"g": pt}}}}}}},
+        {"a": {"b": {"c": {"d": {"e": {"f": pt}}}}}},
+        {"code": "x = round(el, 2)\nreturn os.path", "text": en},
+        {"body": "Traceback:\n  File x.py\nO sistema não está funcionando desde ontem e preciso de ajuda", "id": 7},
+        {"a": "José", "b": "María", "c": "François", "d": en},
+        {"a": en * 70, "b": "Vreau să anulez comanda pentru că produsul este deteriorat."},
+        {"a": en * 70, "b": "Мне дважды списали деньги в этом месяце, верните."},
+        {"a": "ok", "b": "no", "c": "yes"},
+        {},
+        [],
+        [en, pt],
+        [pt, en],
+        [en, en, en, "Die Rechnung ist falsch, bitte korrigieren."],
+        ["hello", "bonjour", "hola"],
+        [1, 2, 3],
+        [None, True, 2.5],
+        [[["deep", ["deeper", [pt]]]]],
+        *deeps,
+        12345,
+        3.5,
+        True,
+        None,
+    ]
+
+
+def fuzz_cases(n, seed):
+    rng = random.Random(seed)
+    pools = [v for v in SENTENCES.values()] + EXTRA + CODE_AND_IDENTIFIERS
+    words = []
+    for s in pools:
+        words.extend(s.split())
+    specials = list("\n\t .,;:=()[]{}/\\@_-'\"") + ["\x1c", "\u00a0", "\u3000", "\u0301", "\u0308",
+                                                   "\u200b", "İ", "ı", "ß", "Σ", "Dž", "Ⅲ", "²",
+                                                   "🙂", "１", "Ａ", "ａ", "ʰ", "ɐ", "é", "ñ"]
+    out = []
+    for _ in range(n):
+        k = rng.randint(1, 40)
+        parts = []
+        for _ in range(k):
+            r = rng.random()
+            if r < 0.75:
+                parts.append(rng.choice(words))
+            else:
+                parts.append(rng.choice(specials))
+        sep = rng.choice([" ", " ", " ", "\n", ""])
+        out.append(sep.join(parts))
+    return out
+
+
+def generated_script_runs():
+    """A run of assigned letters from every script range the detector names."""
+    from laya.lang import _SCRIPT_RANGES
+    out = []
+    for name, ranges in _SCRIPT_RANGES:
+        for lo, hi in ranges:
+            letters = [chr(cp) for cp in range(lo, hi + 1)
+                       if unicodedata.category(chr(cp)) != "Cn"]
+            if not letters:
+                continue
+            step = max(1, len(letters) // 24)
+            sample = letters[::step][:24]
+            out.append("".join(sample))
+            out.append(" ".join("".join(sample[i:i + 4]) for i in range(0, len(sample), 4)))
+    return out
+
+
+def assigned(s):
+    return all(unicodedata.category(c) != "Cn" and not (0xD800 <= ord(c) <= 0xDFFF) for c in s)
+
+
+def sorted_keys(v):
+    if isinstance(v, dict):
+        return list(v) == sorted(v) and all(sorted_keys(x) for x in v.values())
+    if isinstance(v, list):
+        return all(sorted_keys(x) for x in v)
+    return True
+
+
+def all_strings(v):
+    if isinstance(v, str):
+        yield v
+    elif isinstance(v, dict):
+        for x in v.values():
+            yield from all_strings(x)
+    elif isinstance(v, list):
+        for x in v:
+            yield from all_strings(x)
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--out", required=True)
+    ap.add_argument("--fuzz", type=int, default=400)
+    ap.add_argument("--seed", type=int, default=339)
+    args = ap.parse_args()
+
+    states = []
+    for name, s in SENTENCES.items():
+        states.append(s)
+        ascii_s = "".join(c for c in unicodedata.normalize("NFKD", s) if not unicodedata.combining(c))
+        if ascii_s != s:
+            states.append(ascii_s)
+        states.append(s.upper())
+        states.append(" ".join(s.split()[:3]))
+    states += EXTRA + CODE_AND_IDENTIFIERS + MULTILINE + budget_cases()
+    states += generated_script_runs()
+    states += structured_cases()
+    # Pairwise mixes: one English and one foreign line, both orders.
+    for name, s in SENTENCES.items():
+        if not name.startswith("en"):
+            states.append(SENTENCES["en"] + "\n" + s)
+            states.append(s + " " + SENTENCES["en"])
+    states += fuzz_cases(args.fuzz, args.seed)
+
+    cases, seen = [], set()
+    for st in states:
+        key = json.dumps(st, ensure_ascii=False, sort_keys=False)
+        if key in seen:
+            continue
+        seen.add(key)
+        assert sorted_keys(st), "mapping keys must be sorted: %r" % (st,)
+        if not all(assigned(s) for s in all_strings(st)):
+            continue
+        det = analyse(st)
+        # Recorded separately because a JSON reader that does not keep key
+        # order loses the profile's order, which the reference defines.
+        rec = {"state": st, "leaves": _iter_text(st), "analysis": det,
+               "profile_order": list(det["script_profile"])}
+        if isinstance(st, str):
+            rec["words"] = _WORD.findall(st)
+        cases.append(rec)
+
+    header = {
+        "laya_version": laya.__version__,
+        "python": sys.version.split()[0],
+        "unidata_version": unicodedata.unidata_version,
+        "fuzz_seed": args.seed,
+    }
+    with open(args.out, "w") as f:
+        json.dump({"header": header, "cases": cases}, f, ensure_ascii=False, indent=0)
+    print("%d cases" % len(cases), file=sys.stderr)
+
+
+if __name__ == "__main__":
+    main()