[Tutor] OverflowError: cannot fit 'long' into an index-sized integer

[Danny Yoo]

Hi Keith,

Ah, good point.  I did not realize that we could use a sqrt() to get a
good upper bound on what primes we can consider.  That cuts down on
the size of the search space enormously.  Ok, I take my objection back
then.

(That being said, I'm fairly certain that this problem can be solved
in constant space, without maintaining an explicit sieve.)