DoTheSimplestThingThatCouldPossiblyWork but don't refactor. When you use addition in place of multiplication.
You can be of two minds about BruteForceSolutions. Sometimes they might not scale, but other times EmbarrassinglyParallel is the goal. http://www.lacim.uqam.ca/~plouffe/Simon/articlepi.html ( Broken Link )
See also: BruteForce, SuperOverGeneralized