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 <bits/stdc++.h>
using namespace std;
 
int main() {
  char in;
  cin>>in;
  
  if(in=='A'){
    cout<<'T'<<endl;
  }
  else if(in=='T'){
    cout<<'A'<<endl;
  }
  
  else if(in=='G'){
    cout<<'C'<<endl;
  }
  
  else if (in=='C'){
    cout<<'G'<<endl;
  } 
}