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 PHP (5.6.30) (judge verdict: Wrong Answer)

$bases = [
  'A' => 'T',
  'T' => 'A',
  'C' => 'G',
  'G' => 'C'
 ];

echo $bases[fscanf(STDIN, "%s", $input)];