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: Accepted)

(defun solve (b)
  (cond
    ((string-equal b "A") "T")
    ((string-equal b "T") "A")
    ((string-equal b "G") "C")
    ((string-equal b "C") "G")))

(defun main ()
  (let ((b (read)))
    (format t "~A~%" (solve b))))

(main)