N, K = map(int, input().split())
S = input()
SN1 = []
SN2 = []
for i in range(N - 1):
    if S[i] == S[i + 1] == '1':
        x = '0'
    else:
        x= '1'
    SN1.append(x)
for i in range(N - 2):
    if SN1[i] == SN1[i + 1] == '1':
        x = '0'
    else:
        x= '1'
    SN2.append(x)
if (N - 1 - K) % 2 == 0:
    h = (N - 1 - K) // 2
    ans = SN1[h:N - 1 -h]
else:
    h = (N - 2 - K) // 2
    ans = SN2[h:N - 2 -h]
ans = ''.join(ans)
print(ans)