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

#define FOR(i, l, r) for(ll i = l; i < r; i++)
#define rep(i, n) FOR(i, 0, n)
#define FORR(i, l, r) for(ll i = r - 1; i >= l; i--)
#define ALL(ar) begin(ar), end(ar)

template <typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {
    return a < b && (a = b, true);
}
template <typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {
    return a > b && (a = b, true);
}
template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p) {
    is >> p.first >> p.second;
    return is;
}
template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p) {
    os << p.first << ' ' << p.second;
    return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
    for(T &x : v) is >> x;
    return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
    for(size_t i = 0; i < v.size(); i++) os << (i ? " " : "") << v[i];
    return os;
}
//-------------------------------------------------

void solve() {
    int n;
    cin >> n;
    vector<string> s(n);
    cin >> s;

    set<string> st;
    rep(i, n) rep(j, n) if(i != j) st.insert(s[i] + s[j]);

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

int main() {
    int t = 1;
    // cin >> t;
    while(t--) solve();
}