Problem:
Score : 600 points

Problem Statement

Snuke has a blackboard and a set S consisting of N integers.
The i-th element in S is S_i.

He wrote an integer X on the blackboard, then performed the following operation N times:

Choose one element from S and remove it.

Let x be the number written on the blackboard now, and y be the integer removed from S. Replace the number on the blackboard with x \bmod {y}.

There are N! possible orders in which the elements are removed from S.
For each of them, find the number that would be written on the blackboard after the N operations, and compute the sum of all those N! numbers modulo 10^{9}+7.

Constraints

All values in input are integers.

1 \leq N \leq 200

1 \leq S_i, X \leq 10^{5}

S_i are pairwise distinct.

Input

Input is given from Standard Input in the following format:

N X
S_1 S_2 \ldots S_{N}

Output

Print the answer.

Sample Input 1

2 19
3 7

Sample Output 1

3

There are two possible orders in which we remove the numbers from S.

If we remove 3 and 7 in this order, the number on the blackboard changes as follows: 19 \rightarrow 1 \rightarrow 1.

If we remove 7 and 3 in this order, the number on the blackboard changes as follows: 19 \rightarrow 5 \rightarrow 2.

The output should be the sum of these: 3.

Sample Input 2

5 82
22 11 6 5 13

Sample Output 2

288

Sample Input 3

10 100000
50000 50001 50002 50003 50004 50005 50006 50007 50008 50009

Sample Output 3

279669259

Be sure to compute the sum modulo 10^{9}+7.

Solution in Haskell (GHC 7.10.3) (judge verdict: Time Limit Exceeded)

-- https://github.com/minoki/my-atcoder-solutions
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE RankNTypes #-}
import Control.Monad
import Data.Char (isSpace)
import Data.Int (Int64)
import Data.List
import qualified Data.Vector.Unboxed as U
import qualified Data.Vector.Unboxed.Mutable as UM
import qualified Data.ByteString.Char8 as BS
import Control.Monad.ST
import Data.Array.ST
import Control.Monad.Reader
--
import Data.Coerce
import qualified Data.Vector.Generic
import qualified Data.Vector.Generic.Mutable
import qualified Data.Array.Base
import qualified Unsafe.Coerce

type Memo s a = ReaderT (STUArray s (Int,Int) N) (ST s) a

runMemo :: Int -> Int -> (forall s. Memo s a) -> a
runMemo x n action = runST $ do
  arr <- newArray ((0,0),(x,n)) invalidN
  runReaderT action arr

solve :: Int -> Int -> [Int] -> N -> Memo s N
solve !x 0 [] !c = pure $ c * fromIntegral x
solve !x !n ss !c = do
  arr <- ask
  val <- lift $ readArray arr (x,n)
  if val == invalidN
    then do val <- doCalc x n ss
            lift $ writeArray arr (x,n) val
            return $ c * val
    else return $ c * val
  where
    doCalc !x !n ss = case span (> x) ss of
      (ss0,[]) -> pure $ factV U.! n * fromIntegral x
      (ss0,ss1) -> do
        let !m = length ss0
            !q = factV U.! n / factV U.! (n-m)
        s <- sumM [ solve (x `rem` t) (n - k - 1) ts (factV U.! (n-m-1) / factV U.! (n-k-1))
                  | (k, t:ts) <- zip [m..] $ tails ss1
                    -- k + length ts + 1 == n
                    -- k : t より大きいやつ
                  ]
        return (q * s)
-- n == length ss

main = do
  [n,x] <- unfoldr (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine
  -- n <= 200, x <= 10^5
  ss <- U.toList . mergeSortBy (\x y -> compare y x) . U.unfoldrN n (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine
  -- si <= 10^5
  print $ runMemo x n $ solve x n ss 1

factV :: U.Vector N
factV = U.scanl' (*) 1 (U.enumFromN 1 200)

sumM :: (Monad m, Num a) => [m a] -> m a
sumM = foldM (\s a -> (s +) <$> a) 0

---

modulo :: Int64
modulo = 10^9+7
addMod, subMod, mulMod :: Int64 -> Int64 -> Int64
addMod !x !y | x + y >= modulo = x + y - modulo
             | otherwise = x + y
subMod !x !y | x >= y = x - y
             | otherwise = x - y + modulo
mulMod !x !y = (x * y) `rem` modulo

newtype N = N { unwrapN :: Int64 } deriving (Eq)
instance Show N where
  show (N x) = show x
instance Num N where
  (+) = coerce addMod
  (-) = coerce subMod
  (*) = coerce mulMod
  fromInteger n = N (fromInteger (n `mod` fromIntegral modulo))
  abs = undefined; signum = undefined

invalidN :: N
invalidN = N (-1)

{-# RULES
"^9/Int" forall x. x ^ (9 :: Int) = let u = x; v = u * u * u in v * v * v
"^9/Integer" forall x. x ^ (9 :: Integer) = let u = x; v = u * u * u in v * v * v
 #-}

---

exEuclid :: (Eq a, Integral a) => a -> a -> (a, a, a)
exEuclid !f !g = loop 1 0 0 1 f g
  where loop !u0 !u1 !v0 !v1 !f 0 = (f, u0, v0)
        loop !u0 !u1 !v0 !v1 !f g =
          case divMod f g of
            (q,r) -> loop u1 (u0 - q * u1) v1 (v0 - q * v1) g r

recipM :: Int64 -> Int64
recipM !x = case exEuclid x modulo of
             (1,a,_) -> a `mod` modulo
             (-1,a,_) -> (-a) `mod` modulo
divM :: Int64 -> Int64 -> Int64
divM !x !y = x `mulMod` recipM y

instance Fractional N where
  (/) = coerce divM
  recip = coerce recipM
  fromRational = undefined

---

mergeSortBy :: (U.Unbox a) => (a -> a -> Ordering) -> U.Vector a -> U.Vector a
mergeSortBy !cmp !vec = doSort vec
  where
    doSort vec | U.length vec <= 1 = vec
               | otherwise = let (xs, ys) = U.splitAt (U.length vec `quot` 2) vec
                             in merge (doSort xs) (doSort ys)
    merge xs ys = U.create $ do
      let !n = U.length xs
          !m = U.length ys
      result <- UM.new (n + m)
      let loop !i !j
            | i == n = U.copy (UM.drop (i + j) result) (U.drop j ys)
            | j == m = U.copy (UM.drop (i + j) result) (U.drop i xs)
            | otherwise = let !x = xs U.! i
                              !y = ys U.! j
                          in case cmp x y of
                               LT -> do UM.write result (i + j) x
                                        loop (i + 1) j
                               EQ -> do UM.write result (i + j) x
                                        UM.write result (i + j + 1) y
                                        loop (i + 1) (j + 1)
                               GT -> do UM.write result (i + j) y
                                        loop i (j + 1)
      loop 0 0
      return result

---

newtype instance UM.MVector s N = MV_N (UM.MVector s Int64)
newtype instance U.Vector N = V_N (U.Vector Int64)

instance Data.Vector.Generic.Mutable.MVector UM.MVector N where -- needs MultiParamTypeClasses here
  basicLength (MV_N mv) = Data.Vector.Generic.Mutable.basicLength mv
  basicUnsafeSlice i l (MV_N mv) = MV_N (Data.Vector.Generic.Mutable.basicUnsafeSlice i l mv)
  basicOverlaps (MV_N mv) (MV_N mv') = Data.Vector.Generic.Mutable.basicOverlaps mv mv'
  basicUnsafeNew l = MV_N <$> Data.Vector.Generic.Mutable.basicUnsafeNew l
  basicInitialize (MV_N mv) = Data.Vector.Generic.Mutable.basicInitialize mv
  basicUnsafeReplicate i x = MV_N <$> Data.Vector.Generic.Mutable.basicUnsafeReplicate i (coerce x)
  basicUnsafeRead (MV_N mv) i = coerce <$> Data.Vector.Generic.Mutable.basicUnsafeRead mv i
  basicUnsafeWrite (MV_N mv) i x = Data.Vector.Generic.Mutable.basicUnsafeWrite mv i (coerce x)
  basicClear (MV_N mv) = Data.Vector.Generic.Mutable.basicClear mv
  basicSet (MV_N mv) x = Data.Vector.Generic.Mutable.basicSet mv (coerce x)
  basicUnsafeCopy (MV_N mv) (MV_N mv') = Data.Vector.Generic.Mutable.basicUnsafeCopy mv mv'
  basicUnsafeMove (MV_N mv) (MV_N mv') = Data.Vector.Generic.Mutable.basicUnsafeMove mv mv'
  basicUnsafeGrow (MV_N mv) n = MV_N <$> Data.Vector.Generic.Mutable.basicUnsafeGrow mv n

instance Data.Vector.Generic.Vector U.Vector N where -- needs MultiParamTypeClasses here
  basicUnsafeFreeze (MV_N mv) = V_N <$> Data.Vector.Generic.basicUnsafeFreeze mv
  basicUnsafeThaw (V_N v) = MV_N <$> Data.Vector.Generic.basicUnsafeThaw v
  basicLength (V_N v) = Data.Vector.Generic.basicLength v
  basicUnsafeSlice i l (V_N v) = V_N (Data.Vector.Generic.basicUnsafeSlice i l v)
  basicUnsafeIndexM (V_N v) i = coerce <$> Data.Vector.Generic.basicUnsafeIndexM v i
  basicUnsafeCopy (MV_N mv) (V_N v) = Data.Vector.Generic.basicUnsafeCopy mv v
  elemseq (V_N v) x y = Data.Vector.Generic.elemseq v (coerce x) y

instance U.Unbox N

--- STUArray s i N

unsafeCoerce_STUArray_N_Int :: STUArray s i N -> STUArray s i Int64
unsafeCoerce_STUArray_N_Int = Unsafe.Coerce.unsafeCoerce
unsafeCoerce_STUArray_Int_N :: STUArray s i Int64 -> STUArray s i N
unsafeCoerce_STUArray_Int_N = Unsafe.Coerce.unsafeCoerce

instance Data.Array.Base.MArray (STUArray s) N (ST s) where
  getBounds arr = Data.Array.Base.getBounds (unsafeCoerce_STUArray_N_Int arr)
  getNumElements arr = Data.Array.Base.getNumElements (unsafeCoerce_STUArray_N_Int arr)
  newArray lu e = unsafeCoerce_STUArray_Int_N <$> Data.Array.Base.newArray lu (coerce e)
  newArray_ lu = unsafeCoerce_STUArray_Int_N <$> Data.Array.Base.newArray_ lu
  unsafeNewArray_ lu = unsafeCoerce_STUArray_Int_N <$> Data.Array.Base.unsafeNewArray_ lu
  unsafeRead arr i = coerce <$> Data.Array.Base.unsafeRead (unsafeCoerce_STUArray_N_Int arr) i
  unsafeWrite arr i e = Data.Array.Base.unsafeWrite (unsafeCoerce_STUArray_N_Int arr) i (coerce e)