#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  int T = 1;
  for (int test_case = 1; test_case <= T; ++test_case) {
    int n, k;
    string s;
    cin >> n >> k >> s;
    map<char, vector<int>> idx;
    for (int i = 0; i < n; ++i) idx[s[i]].push_back(i);
    map<int, bool> used;
    for (char c = 'a'; c <= 'z'; ++c) {
      for (int i = 0; i < (int)idx[c].size() and k; ++i) {
        --k;
        used[idx[c][i]] = true;
      }
    }
    for (int i = 0; i < n; ++i) {
      if (!used[i]) cout << s[i];
    }
  }
}
