#include <iostream>
#include <unordered_set>
#include <vector>

int count_possible_strings(int N, std::vector<std::string>& strings) {
  std::unordered_set<std::string> possible_strings;
  possible_strings.reserve(N * (N - 1));
  for (int i = 0; i < N; ++i) {
    for (int j = i + 1; j < N; ++j) {
      possible_strings.insert(strings[i] + strings[j]);
      possible_strings.insert(strings[j] + strings[i]);
    }
  }
  return possible_strings.size();
}

int main() {
  int N;
  std::cin >> N;
  std::vector<std::string> strings(N);
  strings.reserve(N);
  for (int i = 0; i < N; ++i) {
    std::cin >> strings[i];
  }
  std::cout << count_possible_strings(N, strings) << std::endl;
  return 0;
}