"""

111011100
 1101110
  10111
   011
    1

"""

import sys
from collections import deque

N,K = map(int,input().split())
S = list(map(int,list(input())))

for i in range(min(N-K,2)):
    T = [ (S[i]&S[i+1])^1 for i in range(len(S)-1) ]
    S = T

if len(S) == K:
    print (*S,sep="")
    sys.exit()

S = deque(S)
while len(S) > K+1:
    S.pop()
    S.popleft()
S = list(S)

while len(S) > K:
    T = [ (S[i]&S[i+1])^1 for i in range(len(S)-1) ]
    S = T

print (*S,sep="")