#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

int main(){
    int N;
    cin >> N;

    map<int, int> mp;
    rep(i, 0, N){
        int A;
        cin >> A;
        mp[A]++;
    }

    int ans = 0;
    for(auto m : mp){
        if(m.second == 1){
            ans++;
        }
    }
    cout << ans << endl;

    return 0;
}