#include <iostream>
#include <map>

using namespace std;

int main() {
    int n;
    cin >> n;
    map<int, int> m;
    for (int i = 0; i < n; ++i) {
        int temp;
        cin >> temp;
        m[temp]++;
    }
    int count = 0;
    for (auto j : m) {
        if (j.second == 1) count++;
    }
    cout << count << endl;
    return 0;
}