#include <algorithm>
#include <iostream>
#include <set>
#include <vector>

int main() {
    using namespace std;
    int n;
    cin >> n;
    vector<string> s(n);
    set<string> t;
    for (auto&& i : s)
        cin >> i;
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < n; ++j)
            if (i != j)
                t.insert(s.at(i) + s.at(j));
    cout << t.size() << '\n';
}