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.*;
import java.io.*;


public class Main {
    static char bondBase(char b){
        if(b=='A') return 'T';
        if(b=='T') return 'A';
        if(b=='C') return 'G';
        if(b=='G') return 'C';
        return '?';
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char b = sc.next().charAt(0);
        System.out.println(bondBase(b));
    }
}