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 Go (1.6) (judge verdict: Accepted)

package main

import "fmt"

func main() {
	var c string
	fmt.Scan(&c)
	m := map[byte]byte{
		'A': 'T',
		'T': 'A',
		'G': 'C',
		'C': 'G',
	}
	fmt.Println(string(m[c[0]]))
}