def Run_Length_Encoding(S):
    """ランレングス圧縮

    S:文字列
    """
    if not S:
        return []

    R=[[S[0],1]]

    for i in range(1,len(S)):
        if R[-1][0]==S[i]:
            R[-1][1]+=1
        else:
            R.append([S[i],1])

    return R
#==================================================
def solve():
    N,K=map(int,input().split())
    S=list(map(int,input()))

    A=[0]*(N-1); B=[0]*(N-2)
    for i in range(N-1):
        A[i]=1-S[i]*S[i+1]
    for i in range(N-2):
        B[i]=1-A[i]*A[i+1]

    if len(B)%2==0:
        A,B=B,A

    if K%2==0:
        t=(len(A)-K)//2
        Ans=A[t:len(A)-t]
    else:
        t=(len(B)-K)//2
        Ans=B[t:len(B)-t]
    print(*Ans,sep="")

solve()