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

#include <iostream>
using namespace std;

int main(){
  char c; cin >> c;
  if(c=='A'){cout << 'T';}
  else if(c=='T'){cout << 'A';}
  else if(c=='C'){cout << 'G';}
  else{cout << 'C';}
  
  return 0;
}