#include <iostream>
#include <set>
#include <vector>
using namespace std;

int main(){
	int N;
	cin >> N;
	
	vector<string> V(N);
	for (auto& v : V) cin >> v;
	
	set<string> S;
	
	for (int i = 0; i < N; i++) {
		for (int j = 0; j < N; j++) {
			if (i != j)
				S.insert(V[i] + V[j]);
		}
	}
	
	cout << S.size() << endl;
	
	return 0;
}