#include <iostream>
#include <vector>
#include <string>

int main(void){
    
    //値の取得
    //-------------------------------
    int N{ 0 };
    std::cin >> N;
    std::vector<std::string> strs;
    
    for(int i{ 0 };i < N; ++i){
        std::string str;
        std::cin >> str;
        strs.push_back(str);
    }
    //-------------------------------
    
    //アルゴリズム
    //-------------------------------
    std::vector<std::string> catStrs;
    
    for(int i = 0; i < N; ++i){
        for(int j = 0; j < N; ++j){
            if(i != j){
                if(catStrs.empty()){
                    catStrs.push_back(strs[i]+strs[j]);
                }else{
                    for(const std::string& cs: catStrs){
                        if( cs != (strs[i]+strs[j]) ){
                            catStrs.push_back(strs[i]+strs[j]);
                        }
                    }
                }
            }
        }
    }
    //-------------------------------
    
    std::cout << catStrs.size() << std::endl;

}