#include <iostream>
#include <iomanip>
#include <cstring>
#include <cmath>
using namespace std;
int main()
{
int n, m,num;
cin >> n;
char str[100006], str1[100006],str2[100006],str3[100006];
char ch, temp;
cin >> str;
cin >> m;
int i, j, s, k;
strcpy(str2, str);
strcpy(str3, str);
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
{
if (str2[i] < str2[j])
{
temp = str2[i];
str2[i] = str2[j];
str2[j] = temp;
}
}
}
num=0;
str1[0]=str[0];
for (i = 1; i < n; i++)
{
for (j = 0; j < n; j++)
{
if (str2[num] == str[j])
{
str1[i] = str[j];
num = j;
str[j]='0';
break;
}
}
}
for (i=0,j= m-1; i < n; i++,j++)
{
if(j==n)
{
j=0;
}
cout <<str1[j];
}
return 0;
}