#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using llu = long long unsigned;

// メイン関数
int main() {
    int n;
    cin >> n;
    vector<string> s(n);
    for (int i=0; i<n; ++i) {
        cin >> s[i];
    }
    set<string> data;
    for (int i=0; i<n; ++i) {
        for (int j=0; j<n; ++j) {
            if (i==j) continue;
            data.insert(s[i]+s[j]);
        }
    }
    cout << data.size() << endl; return 0;
}