#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const int MAX = 400005;
const int MAX1 = 2007;
const int MAX2 = 4007;
const int LEN = 21;
const int BASE = 1000000000;
const double EPS = 1e-7;
const int MOD = 1234567891;
vector<pair<char, int> > vec;
int main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ifstream in("");
  ofstream out("");
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  for (int i = (0); i < ((int)s.size()); ++i) {
    vec.push_back(make_pair(s[i], i));
  }
  sort(vec.begin(), vec.end());
  char ans[MAX];
  memset(ans, '\0', sizeof(ans));
  for (int i = (k); i < ((int)vec.size()); ++i) {
    ans[vec[i].second] = vec[i].first;
  }
  for (int i = (0); i < (n); ++i) {
    if (ans[i] != '\0') cout << ans[i];
  }
  cout << endl;
  return 0;
}
