class Solution:

     def getMax(self,B:'List[int]'):

         n = len(B)

         maxlen = 0

         curlen = 0

         for i in range (n):

             if B[i] == 1:

                 curlen += 1

             else:

                 maxlen = max(maxlen,curlen)

                 curlen = 0

         return max(maxlen,curlen)

     def longestOnes(self, A: 'List[int]', K: int) -> int:

         if K == 0:

             return self.getMax(A)

         n = len(A)

         zlist = list()

         for i in range(n):

             if A[i] == 0:

                 zlist.append(i)

         if len(zlist)<=K:

             return n

         maxlen = 0

         for zi in range(len(zlist)-K+1):

             ti = zi+K

             left = 0

             right = len(A)-1

             if zi==0:

                 left = zlist[zi]

             else:

                 left = zlist[zi-1]+1

             if zi == len(zlist)-K:

                 right = len(A) - 1

             else:

                 right = zlist[ti] - 1

             maxlen = max(maxlen, right - left +1)

         return maxlen