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

int main(){
    int N;
    cin >> N;
    vector<string> S(N);
    for(string &s : S) cin >> s;

    set<string> st;
    rep(i, 0, N) rep(j, 0, N){
        if(i == j) continue;
        st.insert(S[i] + S[j]);
    }
    cout << st.size() << endl;

    return 0;
}