#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n >> k;
  string s;
  cin >> s;
  vector<pair<int, int> > v;
  for (int i = 0; i < (n); ++i) v.push_back(make_pair(s[i] - 'a', i));
  sort((v).begin(), (v).end());
  map<int, bool> mp;
  for (int i = 0; i < (k); ++i) mp[v[i].second] = true;
  string t = "";
  for (int i = 0; i < (n); ++i)
    if (!mp.count(i)) t += s[i];
  cout << t << endl;
  return 0;
}
