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 Java (OpenJDK 11.0.6) (judge verdict: Runtime Error)

import java.util.*;
public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt(), Q = sc.nextInt();
		String S = sc.next();
		for (int i=0; i<Q; i++){
			int count = 0;
			int l = sc.nextInt(), r = sc.nextInt();
			String sub = S.substring(l-1, r);
			for (int j=0; j<sub.length()-1; j++){
				if (sub.charAt(j)=='A' && sub.charAt(j+1)=='C'){
					count++;
				}
			}
			System.out.println(count);
		}

	}

}