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 (GNU Fortran 9.2.1) (judge verdict: Accepted)

program prob1
    implicit none
    character :: s
    read(*,*) s
    if(s == 'A') then
        write(*,*) 'T'
    else if(s == 'T') then
        write(*,*) 'A'
    else if(s == 'G') then
        write(*,*) 'C'
    else if(s == 'C') then
        write(*,*) 'G'
    end if
    stop
contains
end program prob1