http://projecteuler.net/problem=9  -  A Pythagorean triplet is a set of three natural numbers, a  b  c, for which,  a2 + b2 = c2 For example, 32 + 42 = 9 + 16 = 25 = 52.  There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the product abc.