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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
using namespace std;

int main ()
{
  char b;
  cin>>b;
  switch (b){
    case 'A' : cout<< 'T' <<endl;
      break;
    case 'T' : cout <<"A\n";
      break;
    case 'G' : cout<<"C\n";
      break;
    default: cout<<"G\n";
  break;}
  return 0;
}