#include <iostream>
#include <algorithm>
using namespace std;
 
int main(){
	int N;
	cin >> N;
	int A[N];
	for(int i = 0; i < N; i++){
		cin >> A[i];
	}
	sort(A, A + N);
	int ans = 0;
	int num = 0;
	bool if_novelty = false;
	for(int i = 0; i < N; i++){
		if(num == A[i]){
			if_novelty = false;
		}else{
			if(if_novelty){
				ans++;
			}
			num = A[i];
			if_novelty = true;
		}
	}
	if(num != A[N - 1] && if_novelty){
		ans++;
	}
	cout << ans << endl;
}