#include <bits/stdc++.h>
using namespace std;
const int m = 1000000007;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  for (int i = 0; i <= 25; i++) {
    for (int j = 0; j < n and k > 0; j++) {
      if (s[j] == 'a' + i) {
        k--;
        s[j] = '0';
      }
    }
  }
  for (auto &x : s) {
    if (x != '0') {
      cout << x;
    }
  }
}
