n, k = map(int, input().split())
s = list(map(int, input()))
while n != k:
    while n % 3 != k % 3:
        t = []
        for i in range(n - 1):
            if s[i] & s[i + 1]:
                t.append(0)
            else:
                t.append(1)
        s = t[:]
        n -= 1
    x = (n - k) // 3
    if x > 0:
        s = s[x:-x]
        n = len(s)
print(*t, sep='')