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 double_helix
  implicit none
  character(1) :: b
  read(*,*) b
  write(*,'(a)') achar(pair(ichar(b)-65)+65)
contains
  integer function pair(n)
    integer, intent(in) :: n
    pair = (228-12*n)/(11*n+12)
  end
end program double_helix