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

using ll = long long;
#define rep(i, n) for(int i = 0; i < n; i++)

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