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'

const main = input => {
	const args = input.split('\n').map(arg => arg.split(' '))
	const b = args[0][0]
	if (b === 'A') console.log('T')
	else if (b === 'C') console.log('G')
	else if (b === 'G') console.log('C')
	else console.log('A')
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))