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(void) {
	char b,s[4];
	scanf("%c", &b);
	s['A'] = 'T';
	s['T'] = 'A';
	s['C'] = 'G';
	s['G'] = 'C';
	printf("%c", s[b]);

	return 0;
}