import std;
import core.bitop;
import core.checkedint;
import core.time;

void main() {
	const n = readln.chomp.to!int;
	auto s = new string[n];
	foreach(i; 0..n) {
		s[i] = readln.chomp;
	}
	string[] t;
	foreach(a; s) {
		foreach(b; s) {
			if(a == b) {
				continue;
			}
			t ~= a ~ b;
		}
	}
	writeln(t.sort.uniq.walkLength);
}