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 Scala (2.11.7) (judge verdict: Accepted)

import scala.math.{min,max}

object Main {
    def main(args: Array[String]) {
        var input = io.Source.stdin.getLines().mkString("\n");
        // val xs = input.split('\n').map(_.toInt).toArray;
        var ss = input.split('\n').toList;
        val s = ss(0);
        val res = if (s(0) == 'A') {
            'T'
        }
        else if (s(0) == 'T') {
            'A'
        }
        else if (s(0) == 'G') {
            'C'
        }
        else {
            'G'
        };
        println(res);
    }
    def to_array_int(s: String): Array[Int] = {
        return s.split(' ').map(_.toInt).toArray;
    }
}