My solution works 0.02 sec :)
It needs only to find all primes from 2 to N and
in addition - O(N) time

> My solution works 0.02 sec :)
> It needs only to find all primes from 2 to N and
> in addition - O(N) time

0.02 sec !!! Must be an extremely clever solution ...
Could you give any further hint following the O(N) hint you gave us
already ???

Thanks,
LG

 i've got this
 1055 C Accepted  0.015 647 KB
-------------------------------
you should do a preprocess ,if m >= [n/2] ,let m be n - m.

So what? I have a solution working 0.01 seconds. It uses Lezandr theorem.