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, c;
	scanf("%c", &b);
	switch(b) {
		case 'A':
			c = 'T';
		break;
		case 'C':
			c = 'G';
		break;
		case 'G':
			c = 'C';
		break;
		case 'T':
			c = 'A';
		break;
	}
	printf("%c", c);
	return 0;
}