#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
typedef long double ld;
typedef long long ll;
typedef vector<vector<int>> Graph;

const ld pi = acos(-1.0);
const ld tau = 2*pi;

const ll MOD = 998244353;
using mint = modint998244353;

const string ABC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
const string abc = "abcdefghijklmnopqrstuvwxyz";
const int dx[8] = {0, -1, 1, 0, -1, 1, -1, 1};
const int dy[8] = {-1, 0, 0, 1, -1, -1, 1, 1};

struct{
    constexpr operator int(){return int(1e9)+1;}
    constexpr operator ll(){return ll(1e18)+1;}
    constexpr auto operator-(){
        struct{
            constexpr operator int(){return -int(1e9)-1;}
            constexpr operator ll(){return -ll(1e18)-1;}
        }_ret;
        return _ret;
    }
}inf;

istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); }
template<int m> istream &operator>>(istream &is, static_modint<m> &a) { long long v; is >> v; a = v; return is; }
template<int m> istream &operator>>(istream &is, dynamic_modint<m> &a) { long long v; is >> v; a = v; return is; }
template<int m> ostream &operator<<(ostream &os, const static_modint<m> &a) { return os << a.val(); }
template<int m> ostream &operator<<(ostream &os, const dynamic_modint<m> &a) { return os << a.val(); }

template<class T> istream &operator>>(istream &is, vector<T> &v) { for (auto &e : v) is >> e; return is; }
template<class T> ostream &operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }

#define Rep(parameter, start, end) for(int parameter = start; parameter < (int)(end); parameter++)
#define rep(parameter, end) Rep(parameter, 0, end)

template<class T> inline bool chmax(T &a,T& b){if(a < b){a = b; return true;} else return false;}
template<class T> inline bool chmin(T &a,T& b){if(a > b){a = b; return true;} else return false;}

template<typename T>
// 全部出力する O(|Vec|)
void declare(T Vec){
    for(auto x : Vec) cout << x << endl;
    return;
}

int main() {
    int N;
    cin >> N;
    vector<string> S(N);
    rep(i, N) cin >> S[i];
    set<string> st;
    for (auto s : S) {
        for (auto t : S) {
            if (s == t) continue;
            st.insert(s+t);
        }
    }
    cout << st.size() << endl;
}

/*



*/