N, K = map(int, input().split())
S = input()
T = ''.join('0' if S[i] == S[i+1] == '1' else '1' for i in range(N-1))
U = ''.join('0' if T[i] == T[i+1] == '1' else '1' for i in range(N-2))
if (N-K) % 2:
    n = (N-K)//2
    print(T[n:N-1-n])
else:
    n = (N-K-2)//2
    print(U[n:N-2-n])