import Control.Applicative ((<$>))

main :: IO ()
main = solve <$> read <$> getLine >>= print

solve :: Int -> Int
solve n = f n 1 1 1
  where f 1 _ _ _ = 1
        f 2 _ _ _ = 2
        f 3 _ kii ki = (kii + ki) `mod` 1000000007
        f i kiii kii ki = f (i-1) kii ki ((kiii + kii) `mod` 1000000007)