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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.* 
fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val b = sc.next()
    val res= if (b == "A") "T"
    else if (b == "T") "A"
    else if (b == "G") "C"
    else "G"
    println(res)
}