### The Story:
Bob is working as a bus driver. However, he has become extremely popular amongst the city's residents. With so many passengers wanting to get aboard his bus, he sometimes has to face the problem of not enough space left on the bus! He wants you to write a simple program telling him if he will be able to fit all the passengers.

### Task Overview:

You have to write a function that accepts three parameters: 
* `cap` is the amount of people the bus can hold excluding the driver.
* `on` is the number of people on the bus.
* `wait` is the number of people waiting to get on to the bus. 

If there is enough space, return 0, and if there isn't, return the number of passengers he can't take.

### Usage Examples:

```python
enough(10, 5, 5)
0 # He can fit all 5 passengers
enough(100, 60, 50)
10 # He can't fit 10 out of 50 waiting
```

```if:csharp
Documentation:
Kata.Enough Method (Int32, Int32, Int32)

Returns the number of passengers the bus cannot fit, or 0 if the bus can fit every passenger.

Syntax


public
static
int Enough(
int cap,
    int on,
int wait
    )
  



Parameters

cap

Type: System.Int32
The amount of people that can fit on the bus excluding the driver.

on

Type: System.Int32
The amount of people on the bus excluding the driver.

wait

Type: System.Int32
The amount of people waiting to enter the bus.

Return Value

Type: System.Int32
  An integer representing how many passengers cannot fit on the bus, or 0 if every passenger can fit on the bus.

```

```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 = 'exec("""\\ndef enough(cap, on, wait):\\n    a = on + wait\\n    b = cap - a \\n    if b >= 0:\\n        return 0\\n    else:\\n        return abs(b)\\n""")'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'enough'
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: 5392