use proconio::{input, marker::Chars};
use std::collections::HashSet;
fn main() {
    input! { n: usize, }
    let mut s: Vec<String> = Vec::new();
    for _ in 0..n {
        input! { a: Chars, };
        s.push(a.iter().collect());
    }
    let mut ans: Vec<String> = Vec::new();
    for i in 0..n {
        for j in 0..n {
            if i == j {
                continue
            }
            let c = format!("{}{}", s[i], s[j]);
            ans.push(c);
        }
    }
    let t: HashSet<_> = ans.iter().collect();
    println!("{}", t.len());
}