#include <bits/stdc++.h>
using namespace std;
int vis[400005];
vector<int> v[26];
int main() {
  int i, j, k, n, m, t;
  cin >> n >> k;
  string s;
  cin >> s;
  for (i = 0; i < s.size(); i++) {
    int cur = s[i] - 97;
    v[cur].push_back(i);
  }
  int cn = 0;
  int f = 1;
  while (cn < k) {
    for (i = 0; i < 26; i++) {
      for (j = 0; j < v[i].size(); j++) {
        vis[v[i][j]] = 1;
        cn += 1;
        if (cn == k) {
          f = 0;
          break;
        }
      }
      if (f == 0) break;
    }
    if (f == 0) break;
  }
  for (i = 0; i < n; i++) {
    if (!vis[i]) cout << s[i];
  }
}
