#include <bits/stdc++.h>
using namespace std;
const int N = 100005, M = 101, MOD = 1e9 + 7;
int n, k;
vector<int> vec;
int freq[26];
string solve2(string s) {
  for (int i = 0; i < s.size(); ++i) {
    freq[s[i] - 'a']++;
  }
  map<char, int> tmp;
  for (int i = 0; i < 26; ++i) {
    if (k > 0) {
      tmp[i + 'a'] = freq[i];
      int h = min(freq[i], k);
      freq[i] -= h;
      k -= h;
    } else
      tmp[i + 'a'] = freq[i];
  }
  string res = "";
  for (int i = 0; i < s.size(); ++i) {
    if (freq[s[i] - 'a'] == tmp[s[i]]) {
      res += s[i];
    } else {
      freq[s[i] - 'a']++;
    }
  }
  return res;
}
int main() {
  ios::sync_with_stdio(false), cin.tie(nullptr);
  memset(freq, 0, sizeof freq);
  cin >> n >> k;
  string s;
  cin >> s;
  cout << solve2(s) << "\n";
  return 0;
}
