use std::{collections::HashSet, io::Read};

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let mut h = HashSet::new();
	let s: Vec<_> = s.split_whitespace().skip(1).collect();
	for i in 0..s.len() {
		for j in i + 1..s.len() {
			h.insert(s[i].to_owned() + s[j]);
			h.insert(s[j].to_owned() + s[i]);
		}
	}
	println!("{}", h.len())
}