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 Fortran (gfortran v4.8.4) (judge verdict: Accepted)

program main
    use,intrinsic :: iso_fortran_env
    implicit none
    character(1):: b

    read*, b
    if (b == 'A') then
        print'(a)', 'T'
    else if (b == 'G') then
        print'(a)', 'C'
    else if (b == 'T') then
        print'(a)', 'A'
    else
        print'(a)', 'G'
    end if
end program main