#include<iostream>
#include<string>
#include<algorithm>
#include<cctype>
#include<set>
#include<bitset>
#include<math.h>
#include<map>
#include<queue>
#include<iomanip>
using namespace std;

int main(){
    int n, cnt = 0;
    cin >> n;
    map<int, int> mp;

    for (int i = 0; i < n; i++){
        int tmp;
        cin >> tmp;
        mp[tmp] += 1;
    }
    for (auto itr = mp.begin(); itr != mp.end(); itr++){
        if (itr->second == 1) cnt++;
    }
    cout << cnt << endl;
}