#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <set>
#include <map>
#include <iomanip>
using namespace std;
using ll = long long;

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