#include <iostream>
#include <vector>
#include <algorithm>
#include <map>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)

using namespace std;

typedef long long int lli;

int main() {
    int N;
    cin >> N;
    map<int, int> A;
    REP (i, 0, N) {
        int a;
        cin >> a;
        A[a]++;
    }
    int cnt = 0;
    for (auto &it: A) {
        int num = it.second;
        cnt += (num == 1);
    }
    cout << cnt << endl;
    return 0;
}