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 12.16.1) (judge verdict: Accepted)

function main(input) {
  const S = input.split('');
  
  if (S[0] === 'A') {
    console.log('T');
  } else if (S[0] === 'T') {
    console.log('A');
  } else if (S[0] === 'C') {
    console.log('G');
  } else if (S[0] === 'G') {
    console.log('C');
  }
}

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