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 main ()
  (let ((s (read-line)))
    (cond ((string= s "A")
           (princ #\T))
          ((string= s "T")
           (princ #\A))
          ((string= s "C")
           (princ #\G))
          ((string= s "G")
           (princ #\C)))))

(main)