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<stdio.h>

int main()
{
  char b,n;


while(1){
  scanf("%s",&b);
  if(b=='A'||b=='T'||b=='C'||b=='G')
    break;
}
  
if(b=='A')  
  printf("T");
else if(b=='T')
  printf("A");
else if(b=='C')
  printf("G");
else if(b=='G')
  printf("C");
  
  return 0;
}