#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define fi first
#define se second
int main(){
    int n;
    cin >> n;
    map<int, int> cnt;
    for(int i = 0; i < n; i++){
        int a;
        cin >> a;
        cnt[a]++;
    }

    int ans = 0;
    for(auto [i, cnt] : cnt){
        if(cnt == 1) ans++;
    }
    cout << ans << endl;
    return 0;
}