Problem:
Score : 100 points

Problem Statement

On the Planet AtCoder, there are four types of bases: A, C, G and T. A bonds with T, and C bonds with G.

You are given a letter b as input, which is A, C, G or T. Write a program that prints the letter representing the base that bonds with the base b.

Constraints

b is one of the letters A, C, G and T.

Input

Input is given from Standard Input in the following format:

b

Output

Print the letter representing the base that bonds with the base b.

Sample Input 1

A

Sample Output 1

T

Sample Input 2

G

Sample Output 2

C

Solution in Rust (1.15.1) (judge verdict: Accepted)


fn input() -> i32 {
    let s = {
        let mut s = String::new();
        std::io::stdin().read_line(&mut s).unwrap();
        s.trim_right().to_owned()
    };
    let mut integers = s.split_whitespace();
    let integer: i32 = integers.next().unwrap().parse().unwrap();
    integer
}
fn input_char() -> char {
    let s = {
        let mut s = String::new();
        std::io::stdin().read_line(&mut s).unwrap();
        s.trim_right().to_owned()
    };
    let ch: char = {
        let mut tmp: char = 'a';
        for c in s.chars() {
            tmp = c
        }
        tmp
    };
    ch
}

fn main() {
    let b: char = input_char();
    if b == 'A' {
        println!("T");
    }
    else if b == 'T' {
        println!("A");
    }
    else if b == 'G' {
        println!("C");
    }
    else {
        println!("G");
    }
}