import Data.List
pf::Integer->Integer->[Integer]
pf p 1 = [1]
pf p n = if n`mod`p==0 then p:pf p(n`div`p) else pf (p+1) n

f (_:[]) = []
f (x:xs) = if elem x xs then f (delete x xs) else x:f xs

main=getLine>>=print.product.f.pf 2.read