N,K=map(int,input().split())
A=[int(a) for a in input()]
for _ in range(2-(N-K)%2):
	B=[0]*(len(A)-1)
	for i in range(len(A)-1):
		B[i]=1-(A[i]&A[i+1])
	A=B.copy()	
t=((N-(2-(N-K)%2)-K)//2)
if t==0:
	print(*B,sep="")
else:
	print(*B[t:-t],sep="")