Envío 7089

Código

import java.util.Scanner;

public class Main{
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        StringBuilder line = new StringBuilder(scanner.nextLine());
        int digit = scanner.nextInt();

        int n = line.length();
        for (int i = n-1; i >= 0; i--) {
            int sum = Character.getNumericValue(line.charAt(i)) + digit;
            if(sum < 10){
                line.setCharAt(i, (char)(sum + '0'));
                break;
            }else{
                digit = 1;
                line.setCharAt(i, (char)(sum % 10 + '0'));
            }
            if(i==0 && String.valueOf(line.charAt(i)).equals("0")){
                line.insert(0,'1');
            }
        }

        System.out.print(line);

        scanner.close();
    }
}