The T9 typing predictor helps with suggestions for possible word combinations on an old-style numeric keypad phone. Each digit in the keypad (2-9) represents a group of 3-4 letters. To type a letter, press once the key which corresponds to the letter group that contains the required letter. Typing words is done by typing letters of the word in sequence.

The letter groups and corresponding digits are as follows:
```
 -----------------
|  1  |  2  |  3  |
|     | ABC | DEF |
|-----|-----|-----|
|  4  |  5  |  6  |
| GHI | JKL | MNO |
|-----|-----|-----|
|  7  |  8  |  9  |
| PQRS| TUV | WXYZ|
 -----------------
```

The prediction algorithm tries to match the input sequence against a predefined dictionary of words. The combinations which appear in the dictionary are considered valid words and are shown as suggestions.

Given a list of words as a reference dictionary, and a non-empty string (of digits 2-9) as input, complete the function which returns suggestions based on the string of digits, which are found in the reference dictionary.

For example:
```python
T9(['hello', 'world'], '43556') returns ['hello']
T9(['good', 'home', 'new'], '4663') returns ['good', 'home']
```

Note that the dictionary must be case-insensitive (`'hello'` and `'Hello'` are same entries). The list returned must contain the word as it appears in the dictionary (along with the case).

Example:
```python
T9(['Hello', 'world'], '43556') returns ['Hello']
```

If there is no prediction available from the given dictionary, then return the string containing first letters of the letter groups, which correspond to the input digits.

For example:
```python
T9([], '43556') returns ['gdjjm']
T9(['gold', 'word'], '4663') returns ['gmmd']
```

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = 'def T9(words, seq):\n    X, res = [\'\', \'\', \'abc\', \'def\', \'ghi\', \'jkl\', \'mno\', \'pqrs\', \'tuv\', \'wxyz\'], ""\n    for i,c in enumerate(map(int, seq)):\n        words = [w for w in words if w[i].lower() in X[c]]\n        res += X[c][0]\n    return words or [res]'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'T9'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 6205