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 {

    private void solve() {
        Scanner sc = new Scanner(System.in);
        String input = sc.next();
        if (input.equals("A")) {
            System.out.println("T");
        }
        else if (input.equals("C")) {
            System.out.println("G");
        }
        else if (input.equals("G")) {
            System.out.println("C");
        }
        else { // T
            System.out.println("A");
        }
    }

    // Main
    public static void main(String[] args) {
        new Main().solve();
    }

}