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 (Clang 3.8.0) (judge verdict: Accepted)

#include <stdio.h>
int main() {
  char b;
  int k;
  scanf("%c",&b);
  if (b =='A') {
    printf("%c\n",'T');
  }else if(b == 'T'){
    printf("%c\n",'A');
  }else if (b == 'G') {
    printf("%c\n",'C' );
  }else{
    printf("%c\n",'G');
  }
  return 0;
}