def solve(n, k, s):
    def conv(s):
        n = len(s)
        return [1 - s[i] * s[i + 1] for i in range(n - 1)]

    for _ in range(2):
        s = conv(s)
        if len(s) == k:
            return s

    # len(s) - 2 * r >= k
    r = (len(s) - k - 1) // 2
    if r > 0:
        s = s[r:-r]

    while len(s) > k:
        s = conv(s)
    return s


def main():
    n, k = list(map(int, input().split()))
    s = [int(x) for x in input().rstrip()]
    ans = solve(n, k, s)
    print("".join(str(x) for x in ans))


main()