fn main() {
    let mut t = String::new();
    std::io::stdin().read_line(&mut t).ok();
    let t: usize = t.trim().parse().unwrap();
    for _ in 0..t {
        let mut s = String::new();
        std::io::stdin().read_line(&mut s).ok();
        let mut s: Vec<usize> = s.trim().chars().map(|c| c.to_string().parse().unwrap()).collect();
        while s.len() > 1 {
            let mut next_s: Vec<usize> = vec![];
            for i in 0..s.len()-1 {
                let ee = s[i];
                let er = s[i+1];
                next_s.push((ee + er) % 10 + (ee + er) / 10);
            }
            s = next_s;
        }
        println!("{}", s[0]);
    }
}