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 Ruby (2.3.3) (judge verdict: Accepted)

line = gets
line.chomp!

# /(\d+)\s+(\d+)/ =~ line
# a = $1.to_i
# b = $2.to_i

/(\w+)/ =~ line
a = $1

if (a == 'A') then
  print 'T'
elsif (a == 'T') then
  print 'A'
elsif (a == 'C') then
  print 'G'
elsif (a == 'G') then
  print 'C'
end