#include <bits/stdc++.h>
int main() {
  int n, k;
  std::map<char, int> freq, actual;
  std::string input;
  std::cin >> n >> k >> input;
  for (char i : input) {
    freq[i]++;
    actual[i]++;
  }
  std::map<char, int>::iterator it = actual.begin();
  while (k--) {
    if (it->second == 0) {
      it++;
      k++;
      continue;
    }
    it->second--;
  }
  for (char i : input) {
    if (actual[i] < freq[i]) {
      actual[i]++;
      continue;
    }
    std::cout << i;
  }
  return 0;
}
