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.Map;
import java.util.Scanner;
import java.util.TreeMap;

public class Main {
	public static final char a = 'A';
	public static final char c = 'C';
	public static final char g = 'G';
	public static final char t = 'T';
	public static void main(String [] args) {
		Scanner scanner = new Scanner(System.in);
		char b = scanner.next().charAt(0);
		Map<Character,Character> map = new TreeMap<Character,Character>();
		map.put(a, t);
		map.put(t, a);
		map.put(g, c);
		map.put(c, g);
		System.out.print(map.get(b));
		scanner.close();
	}
}