#include <iostream>
#include <vector>
#include <unordered_map>

using namespace std;

int main() {
    int n;
    vector<int> v;
    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 (auto it = ump.begin(); it != ump.end(); ++it) {
        if (it -> second == 1) {
            ct++;
        }
    }
    
    cout << ct << endl;  
    
    return 0 ;
}