#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  long long n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  long long len = s.length();
  vector<long long> v[26];
  for (long long i = 0; i < len; i++) {
    v[s[i] - 'a'].push_back(i);
  }
  long long cnt = 0;
  for (int i = 0; i < 26; i++) {
    for (auto it = v[i].begin(); it != v[i].end(); it++) {
      s[*it] = '*';
      cnt++;
      if (cnt == k) break;
    }
    if (cnt == k) break;
  }
  for (long long i = 0; i < len; i++) {
    if (s[i] != '*') cout << s[i];
  }
  return 0;
}
