#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    unordered_map<int32_t, int32_t> mp;
    int32_t n;
    cin >> n;
    for (auto i = 0; i < n; ++i) {
        int32_t a;
        cin >> a;
        ++mp[a];
    }
    int32_t ans = 0;
    for (auto &p : mp) {
        if (p.second == 1)
            ++ans;
    }
    cout << ans << endl;
    return 0;
}