#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n];
  for (int i = 0; i < n; i++) cin >> a[i];
  int num = 0;
  int c = 0;
  sort(a, a + n);
  for (int i = 1; i < n; i++) {
    if (a[i] != a[i - 1]) num = i;
    if (num > c) c++;
  }
  cout << c << endl;
}
