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 base, ans;
  scanf("%c", &base);
  if (base == 'A') {
    ans = 'T';
  } else if (base == 'C') {
    ans = 'G';
  } else if (base == 'T') {
    ans = 'A';
  } else {
    ans = 'C';
  }
  printf("%c\n", ans);
  return 0;
}