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.*;

public class Main {
    public static void main(String[] args) throws Exception {
      Scanner sc = new Scanner(System.in);  
      String b = sc.next();
        switch(b) {
            case "A":
                System.out.println("T");
                break;
            case "T":
                System.out.println("A");
                break;
            case "G":
                System.out.println("C");
                break;
            case "C":
                System.out.println("G");
                break;
        }
    }
}