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 JavaScript (node.js v5.12) (judge verdict: Accepted)

"use strict";
function Main(input) {
    let b = input.split("\n")[0].split(/\s/)[0];
    let ans;
    switch (b) {
        case 'A': ans = 'T'; break;
        case 'C': ans = 'G'; break;
        case 'T': ans = 'A'; break;
        case 'G': ans = 'C'; break;
        default: ;
    }
    console.log(ans);
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));