//
// Created by HakuroKawashiro on 2024/4/24.
//
#include <string>
#include <iostream>
#include <set>
using namespace std;
int main() {
    int n;
    cin >> n;
    string str[55];
    for (int i = 1;i <= n;i++) {
        cin >> str[i];
    }
    set<string> s;
    for (int i = 1;i <= n;i++) {
        for (int j = 1;j <= n;j++) {
            if (i != j) {
                s.insert(str[i] + str[j]);
            }
        }
    }
    cout << s.size() << endl;
    return 0;
}