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) throws Exception {

//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);
    	String b = sc.next();
    	sc.close();
    	switch(b){
    	case "A":
    		System.out.println("T");
    		break;
    	case "T":
    		System.out.println("A");
    		break;
    	case "C":
    		System.out.println("G");
    		break;
    	case "G":
    		System.out.println("C");
    		break;
    	default :
    		System.out.println("err");
    	}
    }
}