{-# LANGUAGE NumericUnderscores #-}

import Control.Monad
import Control.Monad.Fix
import Data.Bool
import Data.IORef

main :: IO ()
main = do
  [a, b, n] <- map read . words <$> getLine
  let c   = bool ((a + 1_000_000_007) `div` 2) (a `div` 2)  (even a)
      det = (c * c `mod` 1_000_000_007 + b) `mod` 1_000_000_007
      alp = (c, 1)
      xp  = (1, 0)
  alpha <- newIORef alp
  x     <- newIORef xp
  cache <- newIORef alp
  flip fix n $ \loop i -> do
    when (odd i) $ do
      ca <- readIORef cache
      modifyIORef' x (\i -> mul i ca det)
    modifyIORef' cache (\i -> mul i i det)
    when (i > 0) $ loop (i `div` 2)
  (_, q) <- readIORef x
  print q

mul :: (Int, Int) -> (Int, Int) -> Int -> (Int, Int)
mul (a, b) (c, d) det =
  let p = (a * c `mod` 1_000_000_007 + det * (b * d `mod` 1_000_000_007) `mod` 1_000_000_007) `mod` 1_000_000_007
      q = (a * d `mod` 1_000_000_007 + b * c `mod` 1_000_000_007) `mod` 1_000_000_007
  in (p, q)