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 sc = new Scanner(System.in);

		char b = sc.next().charAt(0);
		char ans = '\u0000';
		switch (b) {
		case 'A':
			ans = 'T';
			break;
		case 'C':
			ans = 'G';
			break;
		case 'G':
			ans = 'C';
			break;
		case 'T':
			ans = 'A';
			break;
		}

		System.out.println(ans);

		sc.close();
	}
}