Envío 4496

Código

import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String inputX = sc.nextLine();
		StringBuilder X = new StringBuilder();
		X.append(inputX);
		X.reverse();
		
		int inputK = sc.nextInt();
		int position = 0;
		int subintX = 0;
		subintX = Integer.parseInt(X.substring(position, position + 1));
		subintX = subintX + inputK;
		X.replace(position, position + 1, Integer.toString(subintX % 10));
		position++;
		
		int size = inputX.length();
		while (subintX > 9) {
			if (position < size) {
				subintX = Integer.parseInt(X.substring(position, position + 1));
				subintX++;
				X.replace(position, position + 1, Integer.toString(subintX % 10));
			} else {
				X.append(1);
				subintX = 0;
			}
			position++;
		} 

		sc.close();
		System.out.println(X.reverse());
	}
}