In a N x N grid composed of 1 x 1 squares, each 1 x 1 square consists of a /, \, or blank space.  These characters divide the square into contiguous regions.
(Note that backslash characters are escaped, so a \ is represented as "\\".)
Return the number of regions.
 













Example 1:
Input:
[
  " /",
  "/ "
]
Output: 2
Explanation: The 2x2 grid is as follows:



Example 2:
Input:
[
  " /",
  "  "
]
Output: 1
Explanation: The 2x2 grid is as follows:



Example 3:
Input:
[
  "\\/",
  "/\\"
]
Output: 4
Explanation: (Recall that because \ characters are escaped, "\\/" refers to \/, and "/\\" refers to /\.)
The 2x2 grid is as follows:



Example 4:
Input:
[
  "/\\",
  "\\/"
]
Output: 5
Explanation: (Recall that because \ characters are escaped, "/\\" refers to /\, and "\\/" refers to \/.)
The 2x2 grid is as follows:



Example 5:
Input:
[
  "//",
  "/ "
]
Output: 3
Explanation: The 2x2 grid is as follows:


 
Note:

1 <= grid.length == grid[0].length <= 30
grid[i][j] is either '/', '\', or ' '.

```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 = "from typing import List\n\nclass DS:\n    \n    def __init__(self, n):\n        self.sizes = [1] * n\n        self.roots = [i for i in range(n)]\n        \n    def query(self, x):\n        root = x\n        while root != self.roots[root]:\n            self.roots[root] = self.roots[self.roots[root]]\n            root = self.roots[root]\n        return root\n    \n    def union(self, x, y):\n        xRoot, yRoot = self.query(x), self.query(y)\n        s, l = (xRoot, yRoot) if self.sizes[xRoot] < self.sizes[yRoot] else (yRoot, xRoot)\n        self.roots[s] = l\n        self.sizes[l] += self.sizes[s] \n\nclass Solution:\n    def regionsBySlashes(self, grid: List[str]) -> int:\n        n = len(grid)\n        nodes = DS(4 * n * n)\n        getIndex = lambda r, c, k: 4 * (n * r + c) + k\n        for i in range(n):\n            for j in range(n):\n                if i > 0: nodes.union(getIndex(i, j, 0), getIndex(i - 1, j, 2))\n                if i < n - 1: nodes.union(getIndex(i, j, 2), getIndex(i + 1, j, 0))\n                if j > 0: nodes.union(getIndex(i, j, 3), getIndex(i, j - 1, 1))\n                if j < n - 1: nodes.union(getIndex(i, j, 1), getIndex(i, j + 1, 3))\n                if grid[i][j] != '/':\n                    nodes.union(getIndex(i, j, 0), getIndex(i, j, 1))\n                    nodes.union(getIndex(i, j, 3), getIndex(i, j, 2))\n                if grid[i][j] != '\\\\\\\\':\n                    nodes.union(getIndex(i, j, 0), getIndex(i, j, 3))\n                    nodes.union(getIndex(i, j, 1), getIndex(i, j, 2))\n        return sum(i == nodes.query(i) for i in range(4 * n * n))"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'regionsBySlashes'
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: 8332