#include <bits/stdc++.h>
using namespace std;
struct node {
  int x, y;
  bool operator<(const node& a) const { return x < a.x || x == a.x && y < a.y; }
};
const int dr[] = {-1, 1, 0, 0, -1, -1, 1, 1};
const int dc[] = {0, 0, -1, 1, -1, 1, -1, 1};
int HH[277];
char s[401000];
int main() {
  int n, k;
  do {
    char _c = getchar(), _v = 1;
    for (n = 0; _c < 48 || _c > 57; _c = getchar())
      if (_c == 45) _v = -1;
    for (; _c >= 48 && _c <= 57;
         n = (n << 1) + (n << 3) + _c - 48, _c = getchar())
      ;
    n *= _v;
  } while (0);
  do {
    char _c = getchar(), _v = 1;
    for (k = 0; _c < 48 || _c > 57; _c = getchar())
      if (_c == 45) _v = -1;
    for (; _c >= 48 && _c <= 57;
         k = (k << 1) + (k << 3) + _c - 48, _c = getchar())
      ;
    k *= _v;
  } while (0);
  scanf("%s", s);
  for (int i = 0; i < n; i++) ++HH[s[i]];
  if (n == k) return 0;
  char c;
  for (c = 'a'; c <= 'z'; ++c) {
    k -= HH[c];
    if (k <= 0) {
      k += HH[c];
      break;
    }
    HH[c] = 0;
  }
  int cnt = 0;
  for (int i = 0; i < n; i++) {
    if (HH[s[i]]) {
      if (s[i] != c)
        putchar(s[i]);
      else {
        cnt++;
        if (cnt > k) putchar(s[i]);
      }
    }
  }
  return 0;
}
