#include "testlib.h"
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const ll MIN_N = 2;
const ll MAX_N = 50;
const ll MIN_Ssize = 1;
const ll MAX_Ssize = 100;
const ll MAX_Ssum = 300;

int main() {
    registerValidation();
    ll N = inf.readLong(MIN_N, MAX_N);
    inf.readEoln();
    ll Ssum = 0;
    set<string> st;
    for(int i=0;i<N;i++){
        string S = inf.readToken("[a-z]{1,100}");
        inf.readEoln();
        Ssum += S.size();
        st.insert(S);
    }
    assert(Ssum <= MAX_Ssum);
    assert((int)st.size() == N);
    set<string> ans;
    for(auto s:st) for(auto t:st) ans.insert(s+t);
    cout << (ans.size() - N) << endl;
    inf.readEof();
}