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)

input = require('fs').readFileSync('/dev/stdin', 'utf8')
lines = input.split('\n')
b = lines.shift()
s = {
    A: 'T',
    C: 'G',
    G: 'C',
    T: 'A'
}
console.log(s[b])