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 b string
        fmt.Scan(&b)

        m := map[string]string{
                "A": "T",
                "T": "A",
                "C": "G",
                "G": "C",
        }

        fmt.Println(m[b])
}