#include <iostream>
#include <unordered_map>

using namespace std;

int main() {
    int n;
    std::unordered_map<int, int> ump;
    
    cin >> n;
    
    int tmp = 0;
    for (int i = 0; i < n; i++) {
        cin >> tmp >> std::ws;
        ump[tmp]++;
    }
    
    int ct = 0;
    for (int i = 0; i < ump.size(); i++) {
        if (ump[i] == 1) {
            ct++;
        }
    }
    
    cout << ct << endl;
    
    return 0 ;
}