this is my code, but wa in test 1, why?
what is the test 1,
thanks
sorry my english is very poor
    import java.io.*;
    import java.util.*;

    public class Main{


        static int sum(int n)
        {
            int sum=n%10+(n/10)%10+(n/100)%10;
            return sum;
        }

        static boolean solve(String n)
        {
            String ant=n.substring(0,3);
            String post=n.substring(3,6);
            if(ant.compareTo(post)==0)
               return true;
            else
            {

            int antn=Integer.parseInt(ant);
            int postn=Integer.parseInt(post);

            int a;
            int b;
            int c;
            int d;
            if(postn+1>999)
            {
                a=antn+1;
                b=0;
            }
            else
            {
                a=antn;
                b=postn+1;
            }
            if(postn-1<0)
            {
                c=antn-1;
                d=999;
            }
            else
            {
                c=antn;
                d=postn-1;
            }
            a=sum(a);
            b=sum(b);
            c=sum(c);
            d=sum(d);

            if(a==b||c==d)
               return true;
            else
             return false;
            }
        }


        public static void main (String args[])
        {
            Scanner in=new Scanner(System.in);
            String n;
            while(in.hasNext())
            {
              n=in.next();
              if(solve(n))
                System.out.println("YES");
              else
                System.out.println("NO");
            }
        }
    }