#include <iostream>
#include <math.h>
#include <algorithm>
#include <functional>
#include <vector>
#include <typeinfo>
#include <climits>
#include <ctype.h>
#include <string>
using namespace std;
#define INIT cin.tie(0); ios::sync_with_stdio(false);
#define FOR(i, a, n) for (int i = a; i < n; i++)
#define REP(i, n) for(int i = 0; i < n; i++)

int main()
{
    INIT;

    int n;
    cin >> n;
    int A[n];
    REP(i, n) cin >> A[i];

    sort(A, A + n);

    int cnt = 0;
    REP(i, n){
        if(i == 0 or i == n - 1){
            if(i == 0){
                if(A[i] != A[i + 1]) cnt++;
            }else{
                if(A[i] != A[i - 1]) cnt++;
            }

        }else{
            if(A[i - 1] != A[i] and A[i] != A[i + 1]) cnt++;
        }
    }
    cout << cnt << endl;

    return 0;
}