output_description: Print the maximum possible number of consecutive people standing on hands
  after at most K directions.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N K
      S
attempt: import numpy
  
  n, k = map(int, input().split(" "))
  
  tmp = [int(i) for i in list(input())]
  person = numpy.array(tmp, dtype=int)
  
  if person[0] == 0:
      first = 0
  else:
      first = 1
  
  length_list = []
  length = 1
  
  pre = first
  
  for i in person[1:]:
      if i == pre:
          length += 1
      else:
          pre = i
          length_list.append(length)
          length = 1
  length_list.append(length)
  
  length_list_len = len(length_list)
  
  if first == 0:
      zero_num = int(length_list_len / 2) + length_list_len % 2
  else:
      zero_num = int(length_list_len / 2)
  
  
  if k > zero_num:
      print(person.shape[0])
  else:
      result = []
      if first == 0:
          result.append(sum(length_list[0 : 2 * k]))
          for i in range(1, zero_num):
              result.append(sum(length_list[2 * i + 1 : 2 * k + 2 * i + 2]))
      else:
          for i in range(zero_num):
              result.append(sum(length_list[2 * i : 2 * k + 2 * i + 1]))
      print(max(result))
  
problem_description: Statement
  
  N people are arranged in a row from left to right.
  
  You are given a string S of length N consisting of `0` and `1`, and a positive
  integer K.
  
  The i-th person from the left is standing on feet if the i-th character of S
  is `0`, and standing on hands if that character is `1`.
  
  You will give the following direction at most K times (possibly zero):
  
  **Direction** : Choose integers l and r satisfying 1 \leq l \leq r \leq N, and
  flip the l-th, (l+1)-th, ..., and r-th persons. That is, for each i = l, l+1,
  ..., r, the i-th person from the left now stands on hands if he/she was
  standing on feet, and stands on feet if he/she was standing on hands.
  
  Find the maximum possible number of **consecutive** people standing on hands
  after at most K directions.
samples: [{"input": "5 1\n    00010", "output": "4\n    \n\nWe can have four consecutive people standing on hands, which is the maximum\nresult, by giving the following direction:\n\n  * Give the direction with l = 1, r = 3, which flips the first, second and third persons from the left.\n\n* * *"}, {"input": "14 2\n    11101010110011", "output": "8\n    \n\n* * *"}, {"input": "1 1\n    1", "output": "1\n    \n\nNo directions are necessary."}]