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 Scala (2.11.7) (judge verdict: Accepted)

import java.util.Scanner

object Main {
  val sc = new Scanner(System.in)
  def main(args: Array[String]): Unit = {
    val b = sc.next
    val res = b.split("(?<=.)").map{ str =>
      str match{
        case "A" => "T"
        case "C" => "G"
        case "G" => "C"
        case "T" => "A"
      }
    }
    res.foreach(print)
    println

  }

}