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: Accepted)

<?php
fscanf(STDIN, "%s", $b);
if($b == "A"){
    echo "T";
}else if($b == "C"){
    echo "G";
}else if($b == "G"){
    echo "C";
}else if($b == "T"){
    echo "A";
}
?>