#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
struct node {
int value,num;
}a[300];
bool cmp1(node x,node y) {return x.value>y.value;}
bool cmp2(node x,node y) {return x.num<y.num;}
int main()
{
string s;
getline(cin,s);
int k;
cin>>k;
int n=s.size();
for(int i=0;i<n-1;i++)
{
a[i].value=s[i]-'0';
a[i].num=i+1;
}
sort(a,a+n,cmp1);
sort(a+k,a+n,cmp2);
for(int i=k;i<=n;i++)
if(a[i].value) cout<<a[i].value;
return 0;
}
