#include <bits/stdc++.h>
using namespace std;
vector<int> v[26];
int main() {
  int n, k;
  cin >> n >> k;
  string x;
  cin >> x;
  for (int i = 0; i < n; i++) {
    v[x[i] - 'a'].push_back(i);
  }
  for (int i = 0; i < 26; i++) {
    if (k <= 0) break;
    for (int j = 0; j < v[i].size(); j++) {
      if (k <= 0) break;
      x[v[i][j]] = '0';
      k--;
    }
  }
  for (int i = 0; i < n; i++)
    if (x[i] != '0') cout << x[i];
}
