#include <iostream>
#include <unordered_map>
using namespace std;
int main(){
    int n;
    cin >> n;
    unordered_map<int, int> hash;
    for(int i = 0; i < n; ++i){
        int temp;
        cin >> temp;
        ++hash[temp];
    }
    int sum = 0;
    for(auto &data : hash){
        sum += (data.second == 1);
    }
    cout << sum << endl;
}