-- yukicoder My Practice
-- author: Leonardone @ NEETSDKASU

main = print . solve =<< readLn

solve n = ans where
    t = filter f $ takeWhile g [1..]
    f x = mod n x == 0
    g x = x * x <= n
    d = if last t ^ 2 == n then -1 else 0
    ans = d + 2 * length t