#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>
#include <limits>
#include <array>

static const int MOD = 998244353;
using ll = long long;
using uint = unsigned;
using ull = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    int n;
    cin >> n;
    vector<string> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    set<string> s;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if(i == j) continue;
            s.emplace(a[i]+a[j]);
        }
    }
    cout << s.size() << "\n";
    return 0;
}