Your task is to define a function that understands basic mathematical expressions and solves them.
For example:

```python
calculate("1 + 1")        # => 2
calculate("18 + 4*6")     # => 42
calculate("245 - 826")    # => -581
calculate("09 + 000482")  # => 491
calculate("8 / 4 + 6")    # => 8
calculate("5 + 1 / 5")    # => 5.2
calculate("1+2+3")        # => 6
calculate("9 /3 + 12/ 6") # => 5
```
Notes:

- Input string will contain numbers (may be integers and floats) and arithmetic operations.
- Input string may contain spaces, and all space characters should be ignored.
- Operations that will be used: addition (+), subtraction (-), multiplication (*), and division (/)
- Operations must be done in the order of operations: First multiplication and division, then addition and subtraction.
- In this kata, input expression will not have negative numbers. (ex: "-4 + 5")
- If output is an integer, return as integer. Else return as float.
- If input string is empty, contains letters, has a wrong syntax, contains division by zero or is not a string, return False.

```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 = "digits = '0123456789'\nops = '+-/*'\n\ndef calc(expr):\n    r = []\n    i = 0\n    t = len(expr)\n    c = ''\n    s = ''\n    left = 0\n    right = 0\n    cur_idx = 0\n    while i < t:\n        c = expr[i]\n        if c in digits:\n            if not s:\n                s = c\n            elif s[-1] in digits:\n                s += c\n            else:\n                r += [s]\n                s = c\n        elif c == ' ':\n            pass\n        elif c in ops:\n            r += [s] if s != '' else []\n            r += [c]\n            s = ''\n        elif c == '(':\n            left = 1\n            right = 0\n            cur_idx = i\n            while i < t and left != right:\n                i += 1\n                if expr[i] == '(':\n                    left += 1\n                elif expr[i] == ')':\n                    right += 1\n            r += [calc(expr[cur_idx+1:i])]\n        i += 1\n    r += [s] if s != '' else []\n    r_new = []\n    for item in r:\n        try:\n            r_new.append(float(item))\n        except ValueError:\n            r_new.append(item)\n    r = list(r_new)\n    r_new = []\n    i = 0\n    t = len(r)\n    while i < t:\n        if r[i] == '-':\n            if type(r[i+1])==float:\n                r_new.append(-r[i+1])\n            elif r[i+1] == '-':\n                sign = 1\n                while r[i+1] == '-':\n                    sign *= -1\n                    i += 1\n                r_new.append(sign * r[i])\n                i -= 1\n            else:\n                r_new.append(r[i])\n                r_new.append(r[i+1])\n            i += 2\n        else:\n            r_new.append(r[i])\n            i += 1\n    r_new = [d for d in r_new if d != '']\n    while '*' in r_new or '/' in r_new:\n        t = len(r_new)\n        mul_idx = r_new.index('*') if '*' in r_new else t\n        div_idx = r_new.index('/') if '/' in r_new else t\n        if mul_idx == 0 or div_idx == 0:\n            raise Exception()\n        cur_idx = min(mul_idx, div_idx)\n        new_numb = r_new[cur_idx-1] * r_new[cur_idx+1] if cur_idx == mul_idx else r_new[cur_idx-1] / r_new[cur_idx+1]\n        r_new = r_new[:cur_idx-1] + [new_numb] + r_new[cur_idx+2:]\n    return sum([d for d in r_new if d != '+'])\n    \n\ndef calculate(x):\n    if x == '':\n        return False\n    try:\n        return calc(x)\n    except:\n        return False"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'calculate'
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: 7588