import sys

int1 = lambda x: int(x) - 1

# input = lambda: sys.stdin.buffer.readline()
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
i1 = lambda: int1(input())
mi = lambda: map(int, input().split())
mi1 = lambda: map(int1, input().split())
li = lambda: list(mi())
li1 = lambda: list(mi1())
lli = lambda n: [li() for _ in range(n)]

INF = float("inf")
mod = int(1e9 + 7)
# mod = 998244353


def next(s):
    a = []
    for j in range(len(s) - 1):
        a.append("0" if s[j : j + 2] == "11" else "1")
    return a


def show(s):
    n = len(s)
    t = [" ".join(list(s))]
    m = [s]
    for i in range(1, n)[::-1]:
        t.append(" " * (n - i) + " ".join(next(m[-1])))
        m.append("".join(next(m[-1])))
    for v in t[::-1]:
        print(v)


n, k = mi()
s = input()

for _ in range(2):
    s = "".join(next(s))
    n -= 1
    if k == n:
        print(s)
        exit(0)

for _ in range(2):
    s = "".join(next(s))
    n -= 1
    if k == n:
        print(s)
        exit(0)
    if (k & 1) == (n & 1):
        d = (n - k) // 2
        print(s[d : n - d])
        exit(0)