#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
int main() {
    // Input
    int N;
    cin >> N;
    vector<int> A(N);
    rep(i, N) cin >> A[i];

    // Count
    map<int, int> cnt;
    rep(i, N) ++cnt[A[i]];

    // Output
    int ans = 0;
    for (const auto& [i, n] : cnt) if (n == 1) ++ans;
    cout << ans << endl;
}