#include <iostream>
#include <stdio.h>
#include <vector>
using namespace std::literals::string_literals;
using i64 = std::int_fast64_t;
using std::cout;
using std::cerr;
using std::endl;
using std::cin;

template<typename T>
std::vector<T> make_v(size_t a){return std::vector<T>(a);}

template<typename T,typename... Ts>
auto make_v(size_t a,Ts... ts){
  return std::vector<decltype(make_v<T>(ts...))>(a,make_v<T>(ts...));
}

int main() {
	int n; scanf("%d", &n); std::vector<std::string> s(n);
	for(int i = 0; i < n; i++) cin >> s[i];

	i64 ans = 0;
	for(int i = 0; i < n; i++) {
		i64 LCP = 1 << 30;
		for(int j = i; j < n; j++) {
			LCP = std::min(LCP, (i64)s[j].size());

			int nxt = 0;
			for(int k = 0; k < LCP; k++) {
				if(s[i][k] != s[j][k]) break;

				nxt = k + 1;
			}
			LCP = nxt;

			if(!LCP) break;
			ans += LCP * (j - i + 1);
		}
	}
	
	printf("%lld\n", ans);
	return 0;
}