#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n); i++)

int main(){
    int n;
    cin >> n;
    map<int, int>m;
    rep(i,n){ int a; cin >> a; m[a]++;}
    cout << count_if(begin(m), end(m), [](auto const& p) { return p.second == 1; }) << endl;
    return 0;
}