import Data.Ratio

main = getLine >>= print . solve . (\[m, n] -> m % n) . map read . words

solve :: Rational -> Integer
solve = err . solve'
    where
        err (Just x) = x
        err _ = -1

solve' :: Rational -> Maybe Integer
solve' x
    | xa == 0 || xb == 0 = Nothing
    | x == (1 % 1) = Just 0
    | x > (1 % 1) && xb == 1 = Just $ xa - 1
    | x > (1 % 1) = solve' (mod xa xb % xb) >>= return . (+ div xa xb)
    | otherwise = solve' (xb % xa) >>= return . (+ 1)
    where
        xa = numerator x
        xb = denominator x