字符串

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scann = new Scanner(System.in);
        String s1 = scann.nextLine();
        String s2 = scann.nextLine();
        int idx1 = s1.length()-1;
        int idx2 = s2.length()-1;
        int c = 0;
        StringBuilder sb = new StringBuilder();
        while(idx1 >= 0 || idx2 >=0 || c > 0){
            int sum = 0;
            if(idx1>=0){
                sum += Integer.parseInt(String.valueOf(s1.charAt(idx1)));
                idx1--;
            }
            if(idx2>=0){
                sum += Integer.parseInt(String.valueOf(s2.charAt(idx2)));
                idx2--;
            }
            sum += c;
            c = sum/10;
            sb.insert(0,sum%10);
        }
        System.out.println(sb.toString());
    }
}