#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  char per = 'a';
  while (k) {
    for (int i = 0; i < n; i++) {
      if (s[i] == per) {
        s[i] = '0';
        k--;
        if (k == 0) {
          break;
        }
      }
    }
    per++;
  }
  for (int i = 0; i < n; i++)
    if (s[i] != '0') cout << s[i];
  return 0;
}
