#include <bits/stdc++.h>

#define rep(i, n) for (int (i) = 0; (i) < (int)(n); (i)++)

const int dx[] = {1, 0, -1, 0};
const int dy[] = {0, 1, 0, -1};
using namespace std;
typedef long long ll;

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    map<int, int> mm;
    int N;
    cin >> N;
    for (int i = 0; i < N; i++) {
        int x;
        cin >> x;
        mm[x]++;
    }
    int ans = 0;
    for (auto it : mm) {
        if (it.second == 1) ans++;
    }
    cout << ans << endl;
    return 0;
}