#include <bits/stdc++.h>
using namespace std;
int arra[130];
int main() {
  int n, k;
  cin >> n >> k;
  vector<char> v(n);
  for (int i = 0; i < n; i++) {
    cin >> v[i];
    arra[v[i]]++;
  }
  for (int i = 97; i <= 122 and k > 0; i++) {
    int tmp = min(arra[i], k);
    k -= tmp, arra[i] -= tmp;
  }
  string ans;
  for (int i = n - 1; i >= 0; i--) {
    if (arra[v[i]]) ans.push_back(v[i]), arra[v[i]]--;
  }
  reverse(ans.begin(), ans.end());
  cout << ans;
  return 0;
}
