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;

namespace algorithm
{
	class Program
	{
		static void Main(string[] args)
		{
			Dictionary<string, string> t =
			new Dictionary<string, string>();

			t.Add("A", "T");
			t.Add("T", "A");
			t.Add("C", "G");
			t.Add("G", "C");
			Console.WriteLine(t[Console.ReadLine()]);
		}

	}
}