We need a function (for commercial purposes) that may perform integer partitions with some constraints.
The function should select how many elements each partition should have.
The function should discard some "forbidden" values in each partition.
So, create ```part_const()```, that receives three arguments.
```part_const((1), (2), (3))```
```
(1) - The integer to be partitioned

(2) - The number of elements that each partition should have

(3) - The "forbidden" element that cannot appear in any partition
```
```part_const()``` should output the amount of different integer partitions with the constraints required.

Let's see some cases:
```python
part_const(10, 3, 2) ------> 4 

/// we may have a total of 8 partitions of three elements (of course, the sum of the elements of each partition should be equal 10) :
[1, 1, 8], [1, 2, 7], [1, 3, 6], [1, 4, 5], [2, 2, 6], [2, 3, 5], [2, 4, 4], [3, 3, 4]

but 2 is the forbidden element, so we have to discard [1, 2, 7], [2, 2, 6], [2, 3, 5] and [2, 4, 4] 

So the obtained partitions of three elements without having 2 in them are:
[1, 1, 8], [1, 3, 6], [1, 4, 5] and [3, 3, 4] (4 partitions)///
```

```part_const()``` should have a particular feature:

 if we introduce ```0``` as the forbidden element, we will obtain the total amount of partitions with the constrained number of elements.

In fact, 
```python
part_const(10, 3, 0) ------> 8 # The same eight partitions that we saw above.
```

Enjoy it and happy coding!!

```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 part_const(n, size, forbidden):\n\n    ways, k, partitions = [0, n] + [0] * (n - 1), 1, 0\n    while k:\n        x, y, k = ways[k-1] + 1, ways[k] - 1, k -1\n        while x <= y:\n            ways[k] = x\n            y, k = y - x, k + 1\n        ways[k] = x + y\n        if len(ways[:k + 1]) == size and forbidden not in ways[:k + 1]: partitions +=  1\n    return partitions'
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'part_const'
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: 5748