#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
void solve() {
  ll n, k;
  string s;
  cin >> n >> k >> s;
  vector<vector<ll>> a(26);
  for (long long i = 0; i < n; i++) {
    a[s[i] - 'a'].push_back(i);
  }
  for (long long i = 0; i < 26; i++) {
    ll r = 0;
    while (k > 0 && r < a[i].size()) {
      s[a[i][r]] = '?';
      k--;
      r++;
    }
  }
  for (long long i = 0; i < n; i++) {
    if (s[i] != '?') cout << s[i];
  }
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ll t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
