#include <bits/stdc++.h>
using namespace std;
queue<int> v[30];
bool ara[10000007];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  string s;
  cin >> n >> k;
  cin >> s;
  for (int i = 0; i < n; i++) {
    v[s[i] - 'a'].push(i);
  }
  int i = 0;
  while (k--) {
    while (v[i].empty()) i++;
    int a = v[i].front();
    ara[a] = 1;
    v[i].pop();
  }
  for (int i = 0; i < n; i++) {
    if (ara[i] == 0) cout << s[i];
  }
  cout << "\n";
  return 0;
}
