use std::io::Read;

fn main() {
	let mut s = String::new();
	std::io::stdin().read_to_string(&mut s).ok();
	let v = s.split_whitespace().skip(1);
	for s in v {
		let mut c: Vec<_> = s.chars().flat_map(|c| c.to_digit(10)).collect();
		while c.len() > 1 {
			c = c
				.windows(2)
				.map(|n| (n[0] + n[1]) / 10 + (n[0] + n[1]) % 10)
				.collect();
		}
		println!("{}", c[0]);
	}
}