#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  string s, st;
  cin >> n >> k;
  cin >> s;
  for (int i = 97; i <= 122; i++) {
    for (int j = 0; j < n; j++) {
      if (s[j] == char(i)) {
        s[j] = '0';
        k--;
      }
      if (k == 0) {
        break;
      }
    }
    if (k == 0) {
      break;
    }
  }
  for (int i = 0; i < n; i++) {
    if (s[i] != '0') {
      st.push_back(s[i]);
    }
  }
  cout << st;
  return 0;
}
