Thank you ,you are smart. I give the total solutions for you.
jinjing
2010-10-12 10:32:48
( reads)
a=513+n,b=513+n-1 c=513-n-1 and d=513-n-2. 1<=n<=511
皆兄弟也
2010-10-12 15:33:34a=513+n,b=513+n-1 c=513-n-1 and d=513-n-2. 1<=n<=511. I lik