#include<bits/stdc++.h>
using namespace std;
int n,k,a[260],rest,t=1,minn,cnt=0;
bool flag=0;
string num;
int main(){
cin>>num>>k;
n=num.length();
for(int i=1;i<=n;++i) a[i]=num[i-1]-'0';
rest=n-k;
while(cnt<rest){
minn=t;
for(int i=t;i<=k+t;++i) if(a[minn]>a[i]) minn=i;
if(a[minn]) flag=1;
if(flag)cout<<a[minn];
k-=minn-t;
t=minn+1;
cnt++;
}
if(!flag) cout<<0;
return 0;
}