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

K = N-K+1
ans = []
for i in range(N-K+1):
    if K%2 == 0:
        l, r = i+K//2-1, i+K//2
        if S[l] == S[r] == "1":
            ans.append(1)
        else:
            ans.append(0)
    else:
        m = i+K//2
        if S[m] == "1" and (S[m-1] == "1" or S[m+1] == "1"):
            ans.append(1)
        else:
            ans.append(0)
if K%2 == 0:
    for i in range(N-K+1):
        ans[i] ^= 1

print("".join(map(str, ans)))