fn main() {
    let mut xx = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), &mut xx).ok();
    let xx: Vec<&str> = xx.split_whitespace().skip(1).collect();

    let table: Vec<usize> = (0..=9).chain(1..=9).collect();
    let conv = |c: char| c.to_digit(10).unwrap() as usize;

    for &x in &xx {
        let mut x: Vec<usize> = x.chars().map(conv).collect();
        while x.len() > 1 {
            x = x.windows(2).map(|x| table[x[0] + x[1]]).collect();
        }

        println!("{}", x[0]);
    }
}