import Data.List (unfoldr)

fibonacci :: [Integer]
fibonacci = 1 : 1 : zipWith (+) fibonacci (tail fibonacci)

countInRange :: Integer -> Integer -> Int
countInRange a b = length $ takeWhile (<= b) $ dropWhile (< a) fibonacci

main :: IO ()
main = do
    [a, b] <- fmap (map read . words) getLine
    print $ countInRange a b

依旧函数大手子