Given the number pledged for a year, current value and name of the month, return string that gives information about the challenge status:

- ahead of schedule
- behind schedule
- on track
- challenge is completed

Examples:

`(12, 1, "February")` - should return `"You are on track."`

`(12, 1, "March")` - should return `"You are 1 behind schedule."`

`(12, 5, "March")` - should return `"You are 3 ahead of schedule."`

`(12, 12, "September")` - should return `"Challenge is completed."`

Details:
- you do not need to do any prechecks (input will always be a natural number and correct name of the month)
- months should be as even as possible (i.e. for 100 items: January, February, March and April - 9, other months 8)
- count only the item for completed months (i.e. for March check the values from January and February) and it means that for January you should always return `"You are on track."`.

```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 = 'import calendar\n\nM = {calendar.month_name[i]: i - 1 for i in range(1, 13)}\n\n\ndef check_challenge(pledged, current, month):\n    if pledged == current:\n        return "Challenge is completed."\n    m = M[month]\n    per_month, rest = divmod(pledged, 12)\n    todo = per_month * m + (min(rest, m))\n    delta = current - todo\n    if delta == 0 or m == 0:\n        return "You are on track."\n    elif delta > 0:\n        return f"You are {delta} ahead of schedule!"\n    else:\n        return f"You are {-delta} behind schedule."'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'check_challenge'
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: 5526