class Solution:
    def longestOnes(self, a: List[int], k: int) -> int:
        d = [-1]
        for i in range(len(a)):
            if a[i] == 0:
                d.append(i)
        d.append(len(a))
        if k >= len(d)-2:
            return len(a)
        ans = 0
        for i in range(0,len(d)-k-1):
            ans = max(ans, d[i+k+1]-d[i]-1)
        return ans