def nands(c1,c2):
    if c1=='1' and c2=='1':
        return '0'
    return '1'

n,k=map(int,input().split())
s=str(input())
k=n-k

t1=''
t2=''
for i in range(n-1):
    t1 += nands(s[i],s[i+1])
if k==1:
    print(t1)
else:
    for i in range(n-2):
        t2 += nands(t1[i],t1[i+1])
    if k%2==0:
        start=k//2-1
        print(t2[start:start+n-k])
    else:
        start=k//2
        print(t1[start:start+n-k])