#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  vector<char> s;
  map<char, int> a;
  char c;
  for (int i = 0; i < n; i++) {
    cin >> c;
    a[c]++;
    s.push_back(c);
  }
  int counter = 0;
  for (int j = 97; j <= 122; j++) {
    if (a[j] == 0) continue;
    if (counter == k) break;
    int c2 = 0;
    for (int i = 0; i < n; i++) {
      if (a[j] <= c2) break;
      if (counter == k) break;
      if (s[i] == j) {
        s[i] = 0;
        counter++;
        c2++;
      }
    }
  }
  for (vector<char>::iterator it = s.begin(); it != s.end(); ++it) {
    if (*it != 0) cout << *it;
  }
}
