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: Runtime Error)

n, q = gets.split.map(&:to_i)
s = gets

q.times do
  counter = 0
  buf = ""
  l, r = gets.split.map(&:to_i)
  s[l-1..r-1].each_char do |c|
    counter += 1 if buf+c == 'AC'
    buf = c
  end
  puts counter
end