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.Scanner
fun main (args: Array<String>) {
  
  val reader = Scanner(System.`in`)
  val input = reader.next()
  
  var output = ""
  
  when(input){
    "A" -> output = "T"
    "T" -> output = "A"
    "C" -> output = "G"
    "G" -> output = "C"
    else -> output = ""
  }
  
  println(output)
}