#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  vector<int> m;
  for (char i = 'a'; i <= 'z'; i++) {
    char temp = i;
    for (int j = 0; j < n; j++) {
      if (s[j] == temp) m.push_back(j);
    }
  }
  int i = 0;
  while (k) {
    s[m[i]] = 0;
    i++;
    k--;
  }
  for (int i = 0; i < s.size(); i++) {
    if (s[i] != 0) cout << s[i];
  }
  return 0;
}
