n, k = map(int, input().split())
s = input()
if (n-k)%2:
    t = ""
    for i in range(n-1):
        t += "0" if s[i:i+2] == "11" else "1"
    n -= 1
    s = t
if k == n: print(s); exit()
ans = ""
for i in range((n-k)//2, (n-k)//2+k):
    ans += "0" if s[i] == "0" or s[i-1:i+2] == "010" else "1"
print(ans)