
import qualified Data.Vector.Unboxed as U
import qualified Data.Vector as V
import qualified Data.ByteString.Char8 as C
import qualified Data.Array.IO as A
import Debug.Trace
import Data.List
import Control.Monad
import Data.Ord

r :: Int -> IO (U.Vector Int)
r n = U.unfoldrN n (C.readInt . C.dropWhile (==' ')) <$> C.getLine

r' :: IO [Int]
r'  =   unfoldr    (C.readInt . C.dropWhile (==' ')) <$> C.getLine

rp :: IO (Int,Int)
rp  = toTup . unfoldr    (C.readInt . C.dropWhile (==' ')) <$> C.getLine

toTup [a,b] = (a,b)

main :: IO ()
main = do
    [n,m] <- r'
    as' <- replicateM m readLn :: IO [Int]
    let as = (-1):(as' ++ [n+1])
    let dif = map ((fib!!) . pred) $ zipWith (-) (tail as) as
    print $ (foldl' (*) 1 dif) `mod` 1000000007


fib = 0:1:zipWith(+)fib(tail fib)