#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int main()
{
    int N;
    cin >> N;
    string a[N];
    rep(i, N) cin >> a[i];

    set<string> s;
    rep(i, N)
    {
        rep(j, N)
        {
            if (i == j)
                continue;

            string t = a[i] + a[j];
            s.insert(t);
        }
    }

    cout << s.size() << endl;
}