#include <iostream>
#include <vector>
#include <algorithm>

#define ALL(x) (x).begin(),(x).end()

using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    for(int i = 0;i < n;i++){
        cin >> a[i];
    }
    int count = 0;
    sort(ALL(a));
    for(int i = 0;i < n;i++){
        if(i == 0 && a[0] != a[1])count++;
        else if(a[i-1] != a[i] && a[i] != a[i+1])count++;
        else if(i == n-1 && a[i-1] != a[i] )count++;
    }
    cout << count << endl;
    return 0;
}