my code is
#include<stdio.h>
#include<string.h>
int main()
{
    char a[10];
    while(scanf("%s",a)==1)
    {
        long int s1=0,s2=0;
        long int len = strlen(a);
        for(long int i=0;i<len;i++)
        {
            if(i<3)
                s1 = s1 + (a[i]-'0');
            else
                s2 = s2 + (a[i] - '0');
        }
        long int sub = s1 - s2;

        if(sub ==1 || sub== -1)
        {
            if(sub==1)
            {
                long int add = (a[len-1]-'0')+1;
                if(add>9)
                {
                    printf("No\n");
                }
                else
                printf("Yes\n");
            }
            else if(sub == -1)
            {
                if(a[len-1]<1)
                printf("No\n");
                else
                printf("Yes\n");
            }
        }
        else
            printf("No\n");
    }
    return 0;
}

i don't know where is my problem. please help me.

opps. sorry .. i found my mistake..