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 Common Lisp (SBCL 1.1.14) (judge verdict: Wrong Answer)

(princ 
 (if (equal "A" (setq b (read))) "T" 
	(if (equal "T" b) "A" 
	 (if (equal "C" b) "G"
		(if (equal "G" b) "C"
		)))))