#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;

int main() {
    int N;
    cin >> N;
    map<int, int> mp;
    rep(i,N){
        int a;
        cin >> a;
        mp[a]++;
    }

    int ans = 0;
    for (auto itr = mp.begin(); itr != mp.end(); ++itr) {
        if(itr->second==1)
            ans++;
    }

    cout << ans << endl;

    return 0;
}