{-# OPTIONS_GHC -O2 #-}
{-# LANGUAGE BangPatterns          #-}
{-# LANGUAGE CPP                   #-}
{-# LANGUAGE LambdaCase            #-}
{-# LANGUAGE MagicHash             #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE MultiWayIf            #-}
{-# LANGUAGE OverloadedStrings     #-}
{-# LANGUAGE TupleSections         #-}
{-# LANGUAGE TypeFamilies          #-}
{-# LANGUAGE ViewPatterns          #-}

import           Control.Applicative
import           Control.Exception
import           Control.Monad
import           Control.Monad.Primitive
import           Control.Monad.ST
import           Control.Monad.State.Strict
import           Data.Bool
import qualified Data.ByteString             as B
import qualified Data.ByteString.Builder     as B
import qualified Data.ByteString.Char8       as C
import qualified Data.ByteString.Unsafe      as B
import           Data.Char
import qualified Data.Foldable               as F
import           Data.Function
import qualified Data.IntMap.Strict          as IM
import qualified Data.IntSet                 as IS
import qualified Data.List                   as L
import qualified Data.Map.Strict             as M
import           Data.Monoid
import           Data.Ord
import           Data.Primitive.MutVar
import           Data.Ratio
import qualified Data.Set                    as S
import           Data.Tuple
import qualified Data.Vector                 as V
import qualified Data.Vector.Generic         as G
import qualified Data.Vector.Generic.Mutable as GM
import qualified Data.Vector.Unboxed         as U
import qualified Data.Vector.Unboxed.Mutable as UM
import           Debug.Trace
import           Foreign                     hiding (void)
import           GHC.Exts
import qualified System.IO                   as IO
import           Unsafe.Coerce

main :: IO ()
main = do
    [n, m] <- map read.words <$> getLine :: IO [Int]
    xs <- U.unfoldrN n (C.readInt.C.dropWhile isSpace) <$> C.getLine
    ys <- U.unfoldrN m (C.readInt.C.dropWhile isSpace) <$> C.getLine
    print $ solve n m xs ys

solve :: Int -> Int -> U.Vector Int -> U.Vector Int -> IntMod
solve h w xs ys =  U.last
    . V.foldl' stepH (U.replicate (w + 1) 1)
    $ U.convert xs
  where
    stepH prev x = U.scanl' stepW 1
        $ U.zip3 prev (U.tail prev) ys
      where
        stepW acc (ul, u, y)
            | x == y = acc + u
            | otherwise = acc + u - ul

-------------------------------------------------------------------------------
#define MOD 1000000007

modulus :: (Num a) => a
modulus = MOD
{-# INLINE modulus #-}

infixr 8 ^%
infixl 7 *%, /%
infixl 6 +%, -%

(+%) :: Int -> Int -> Int
(I# x#) +% (I# y#) = case x# +# y# of
    r# -> I# (r# -# ((r# >=# MOD#) *# MOD#))
{-# INLINE (+%) #-}

(-%) :: Int -> Int -> Int
(I# x#) -% (I# y#) = case x# -# y# of
    r# -> I# (r# +# ((r# <# 0#) *# MOD#))
{-# INLINE (-%) #-}

(*%) :: Int -> Int -> Int
(I# x#) *% (I# y#) = I# ((x# *# y#) `remInt#` MOD#)
{-# INLINE (*%) #-}

-- |
-- >>> 1 /% 0
-- 0
(/%) :: Int -> Int -> Int
(I# x#) /% (I# y#) = go# y# MOD# 1# 0#
  where
    go# a# b# u# v#
        | isTrue# (b# ># 0#) = case a# `quotInt#` b# of
            q# -> go# b# (a# -# (q# *# b#)) v# (u# -# (q# *# v#))
        | otherwise = I# ((x# *# (u# +# MOD#)) `remInt#` MOD#)
{-# INLINE (/%) #-}

(^%) :: Int -> Int -> Int
x ^% n
    | n > 0 = go 1 x n
    | n == 0 = 1
    | otherwise = go 1 (1 /% x) (-n)
  where
    go !acc !y !m
        | m .&. 1 == 0 = go acc (y *% y) (unsafeShiftR m 1)
        | m == 1 = acc *% y
        | otherwise = go (acc *% y) (y *% y) (unsafeShiftR (m - 1) 1)

newtype IntMod = IntMod{getIntMod :: Int} deriving (Eq, Ord)

intMod :: (Integral a) => a -> IntMod
intMod x = fromIntegral $ mod (fromIntegral x) MOD
{-# INLINE intMod #-}

intModValidate :: IntMod -> Bool
intModValidate (IntMod x) = 0 <= x && x < MOD
{-# INLINE intModValidate #-}

instance Show IntMod where
    show (IntMod x) = show x

instance Bounded IntMod where
    minBound = IntMod 0
    maxBound = IntMod $ modulus - 1

instance Enum IntMod where
    toEnum = intMod
    fromEnum = coerce

instance Real IntMod where
    toRational = coerce (toRational :: Int -> Rational)

instance Integral IntMod where
    quotRem x y = (x / y, x - x / y * y)
    toInteger = coerce (toInteger :: Int -> Integer)

instance Num IntMod where
    (+) = coerce (+%)
    (-) = coerce (-%)
    (*) = coerce (*%)
    abs = id
    signum = const (IntMod 1)
    fromInteger x = (coerce :: Int -> IntMod) . fromInteger $ mod x modulus

instance Fractional IntMod where
    (/) = coerce (/%)
    fromRational q = fromInteger (numerator q) / fromInteger (denominator q)

newtype instance UM.MVector s IntMod = MV_IntMod (UM.MVector s Int)
newtype instance U.Vector IntMod = V_IntMod (U.Vector Int)

instance U.Unbox IntMod

instance GM.MVector UM.MVector IntMod where
    basicLength (MV_IntMod v) = GM.basicLength v
    {-# INLINE basicLength #-}
    basicUnsafeSlice i n (MV_IntMod v) = MV_IntMod $ GM.basicUnsafeSlice i n v
    {-# INLINE basicUnsafeSlice #-}
    basicOverlaps (MV_IntMod v1) (MV_IntMod v2) = GM.basicOverlaps v1 v2
    {-# INLINE basicOverlaps #-}
    basicUnsafeNew n = MV_IntMod `liftM` GM.basicUnsafeNew n
    {-# INLINE basicUnsafeNew #-}
    basicInitialize (MV_IntMod v) = GM.basicInitialize v
    {-# INLINE basicInitialize #-}
    basicUnsafeReplicate n x = MV_IntMod `liftM` GM.basicUnsafeReplicate n (coerce x)
    {-# INLINE basicUnsafeReplicate #-}
    basicUnsafeRead (MV_IntMod v) i = coerce `liftM` GM.basicUnsafeRead v i
    {-# INLINE basicUnsafeRead #-}
    basicUnsafeWrite (MV_IntMod v) i x = GM.basicUnsafeWrite v i (coerce x)
    {-# INLINE basicUnsafeWrite #-}
    basicClear (MV_IntMod v) = GM.basicClear v
    {-# INLINE basicClear #-}
    basicSet (MV_IntMod v) x = GM.basicSet v (coerce x)
    {-# INLINE basicSet #-}
    basicUnsafeCopy (MV_IntMod v1) (MV_IntMod v2) = GM.basicUnsafeCopy v1 v2
    {-# INLINE basicUnsafeCopy #-}
    basicUnsafeMove (MV_IntMod v1) (MV_IntMod v2) = GM.basicUnsafeMove v1 v2
    {-# INLINE basicUnsafeMove #-}
    basicUnsafeGrow (MV_IntMod v) n = MV_IntMod `liftM` GM.basicUnsafeGrow v n
    {-# INLINE basicUnsafeGrow #-}

instance G.Vector U.Vector IntMod where
    basicUnsafeFreeze (MV_IntMod v) = V_IntMod `liftM` G.basicUnsafeFreeze v
    {-# INLINE basicUnsafeFreeze #-}
    basicUnsafeThaw (V_IntMod v) = MV_IntMod `liftM` G.basicUnsafeThaw v
    {-# INLINE basicUnsafeThaw #-}
    basicLength (V_IntMod v) = G.basicLength v
    {-# INLINE basicLength #-}
    basicUnsafeSlice i n (V_IntMod v) = V_IntMod $ G.basicUnsafeSlice i n v
    {-# INLINE basicUnsafeSlice #-}
    basicUnsafeIndexM (V_IntMod v) i = coerce `liftM` G.basicUnsafeIndexM v i
    {-# INLINE basicUnsafeIndexM #-}
    basicUnsafeCopy (MV_IntMod mv) (V_IntMod v) = G.basicUnsafeCopy mv v
    elemseq _ = seq
    {-# INLINE elemseq #-}

type Parser a = C.ByteString -> Maybe (a, C.ByteString)

parseInt :: Parser Int
parseInt = C.readInt . C.dropWhile isSpace

parseInt2 :: Parser (Int, Int)
parseInt2 = runStateT $
    (,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)

parseInt3 :: Parser (Int, Int, Int)
parseInt3 = runStateT $
    (,,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)

parseInt4 :: Parser (Int, Int, Int, Int)
parseInt4 = runStateT $
    (,,,) <$> StateT (C.readInt . C.dropWhile isSpace)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)
        <*> StateT (C.readInt . B.unsafeTail)

Measured memory_bytes: 1404