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 <string.h>

int main() {

  char a[1];

  scanf("%s", a);
  if (strcmp(a, "A") == 0 ) {
    printf("T");
  } else if (strcmp(a, "C") == 0) {
    printf("G");
  } else if (strcmp(a, "G") == 0) {
    printf("C");
  } else {
    printf("A");
  }
  return 0;
}