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>
#include<math.h>
#include <stdlib.h>
int main()
{
    char a,b;

    scanf("%c", &b);
	/*printf("%c",b);*/
    if(b=='A'){
      a='T';
    } else if (b=='T'){
      a='A';
    } else if (b=='G'){
      a='C';
    } else {
      a='G';
    }

    printf("%c",a);
    return 0;
}