Python. 2 Liner. using Lambda function and LRU cache///
\nclass Solution:\n    def minimumWhiteTiles(self, x: str, n: int, cl: int) -> int:\n        f=lru_cache(None)(lambda i,n: 0 if i>=len(x) else min((1 if x[i]==\
```\nclass Solution:\n    def minimumWhiteTiles(self, x: str, n: int, cl: int) -> int:\n        f=lru_cache(None)(lambda i,n: 0 if i>=len(x) else min((1 if x[i]==\'1\' else 0)+f(i+1,n),(inf if n==0 else f(i+cl,n-1))))\n        return f(0,n)\n```
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