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