Problem:
Score : 100 points

Problem Statement

An uppercase or lowercase English letter \alpha will be given as input.
If \alpha is uppercase, print A; if it is lowercase, print a.

Constraints

\alpha is an uppercase (A - Z) or lowercase (a - z) English letter.

Input

Input is given from Standard Input in the following format:

α

Output

If \alpha is uppercase, print A; if it is lowercase, print a.

Sample Input 1

B

Sample Output 1

A

B is uppercase, so we should print A.

Sample Input 2

a

Sample Output 2

a

a is lowercase, so we should print a.

Solution in Rust (1.42.0) (judge verdict: Accepted)

fn main() {
    let a: char = read();
    println!("{}", solve(a));
}

fn read<T: std::str::FromStr>() -> T {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).ok();
    buf.trim().parse().ok().unwrap()
}

fn solve(c: char) -> char {
    if 'a' <= c && c <= 'z' {
        'a'
    } else {
        'A'
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_solve_1() {
        assert_eq!('A', solve('B'));
    }

    #[test]
    fn test_solve_2() {
        assert_eq!('a', solve('a'));
    }
}