def f(S):
    ANS = []
    m = len(S)
    for i in range(m - 1):
        if S[i] == S[i + 1] == '1':
            ANS.append('0')
        else:
            ANS.append('1')
    return ''.join(ANS)

n, k = map(int, input().split())
S = list(input())
s1 = f(S)
s2 = f(s1)
if (n - k) % 2 == 1:
    m = (n - k) // 2
    ans = s1[m:n - 1 - m]
else:
    m = (n - k - 2) // 2
    ans = s2[m:n - 2 - m]
print(ans)