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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;//
public class A{
    public static void Main(){
        string b = Console.ReadLine();//Read()だとint型といわれる
        Dictionary<string, string> dic = new Dictionary<string, string>();
        
        dic.Add("A","T");
        dic.Add("T","A");
        dic.Add("C","G");
        dic.Add("G","C");
        
        Console.WriteLine(dic[b]);
    }
}