{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE BinaryLiterals #-}
{-# LANGUAGE MultiWayIf #-}
{-# LANGUAGE NumDecimals #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE FlexibleContexts #-}

{-# OPTIONS_GHC -O2 #-}
{-# OPTIONS_GHC -Wno-tabs #-}

import Control.Applicative
import Control.Arrow
import Control.Monad
import Control.Monad.ST

import Data.Char
import Data.List
import Data.Maybe
import Data.Either
import Data.Bool

import qualified Data.ByteString.Char8 as B

import Data.Array
import Data.Array.ST.Safe
import Data.STRef

import Debug.Trace
import Text.Printf

readInt = fst . fromJust . B.readInt <$> B.getLine
readInteger = fst . fromJust . B.readInteger <$> B.getLine
readInts = map ( fst . fromJust . B.readInt ) . B.words <$> B.getLine
readIntegers = map ( fst . fromJust . B.readInteger ) . B.words <$> B.getLine
readStr = head <$> readStrs
readStrs = map B.unpack . B.words <$> B.getLine

yesno = bool "No" "Yes"
mp [ a, b ] = ( a, b )

modifyArray a i f = writeArray a i =<< f <$> readArray a i

printList :: Show a => [a] -> IO ()
printList = putStrLn . intercalate " " . map show

main = do
	[ n, t ] <- readInts
	ts <- readInts
	k <- readInt
	cs <- elems . accumArray (+) 0 ( 1, n ) . flip zip ( repeat 1 ) <$> readInts
	print $ fromMaybe (-1) $ solve t 0 cs ts

solve _ _ _ [] = Just 0
solve cnt s (c:cs) (t:ts)
	| 0 < cnt - t = solve ( cnt - t ) ( s + c ) cs ts
	| 0 < cnt + ( s + c ) * 10 - t = ( need + ) <$> solve ( cnt + need * 10 - t ) ( s + c - need ) cs ts
	| otherwise = Nothing
	where
	need = ( -( cnt - t ) + 10 ) `div` 10