#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k, i, flag;
  char del = 'a';
  cin >> n >> k;
  char str[n];
  cin >> str;
  while (del <= 'z') {
    if (k == 0) break;
    flag = 0;
    for (i = 0; i < n; i++) {
      if (str[i] == del) {
        str[i] = '0';
        k--;
        flag = 1;
      }
      if (k == 0) break;
    }
    if (flag == 0) del++;
  }
  for (i = 0; i < n; i++) {
    if (str[i] != '0') cout << str[i];
  }
}
