import sys
input = sys.stdin.readline
from collections import deque

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

def calc(S):
    A=["1"]*(len(S)-1)
    for i in range(len(S)-1):
        if S[i]=="1" and S[i+1]=="1":
            A[i]="0"
    return A

for i in range(100):
    if len(S)>=K+1:
        S=calc(S)
    else:
        break

S=deque(S)
while len(S)>=K+2:
    S.popleft()
    S.pop()

S=list(S)
if len(S)==K:
    print("".join(S))
else:
    S=calc(S)
    print("".join(S))