// No.182 新規性の虜
// https://yukicoder.me/problems/no/182
//
#include <iostream>
#include <unordered_map>
using namespace std;

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

    unordered_map<int, int> numbers;
    for (auto i = 0; i < N; ++i) {
        int tmp;
        cin >> tmp;
        numbers[tmp]++;
    }

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