#include<bits/stdc++.h>
#define rep(i,a,n) for (int i = a;i < n;i++)
#define per(i,n,a) for (int i = n-1;i >= a;i--)
using namespace std;

int main() {
    int n;
    cin >> n;
    vector<int> A(n);
    map<int, int> m;
    rep(i,0,n) {
        cin >> A[i];
        m[A[i]]++;
    }
    int ans = 0;
    for (auto i: m) {
        if (i.second == 1) ans++;
    }
    cout << ans << endl;
}