/* -*- coding: utf-8 -*-
 *
 * 2334.cc:  No.2334 Distinct Cards - yukicoder
 */

#include<cstdio>
#include<algorithm>
 
using namespace std;

/* constant */

const int MAX_N = 100000;

/* typedef */

/* global variables */

int as[MAX_N], cs[MAX_N];

/* subroutines */

/* main */

int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  for (int i = 0; i < n; i++) scanf("%d", as + i);
  sort(as, as + n);

  int m = 0;
  for (int i = 0; i < n;) {
    int j = i;
    while (i < n && as[j] == as[i]) i++;
    cs[m++] = i - j;
  }
  sort(cs, cs + m);

  int l = 0, s = 0;
  for (int i = m - 1; i >= 0 && s < k; i--)
    s += cs[i], l++;

  printf("%d\n", l);
  return 0;
}