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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    String input = scanner.nextLine();
    switch(input) {
      case "A":
        System.out.println("T");
        break;
      case "C":
        System.out.println("G");
        break;
      case "T":
        System.out.println("A");
        break;
      case "G":
        System.out.println("C");
        break;
      default:
        System.out.println("Please input only A/C/T/G");
        break;
    }
  }
}