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(void) {
	static const char horieyui[256] = {
		['A'] = 'T', ['T'] = 'A', ['C'] = 'G', ['G'] = 'C'
	};
	char b[4];
	if (scanf("%3s", b) != 1) return 1;
	printf("%c\n", horieyui[(unsigned char)b[0]]);
	return 0;
}