{-# OPTIONS_GHC -O2 #-}
{-# LANGUAGE TypeApplications #-}
{-# LANGUAGE Strict #-}
{-# LANGUAGE StrictData #-}
import qualified Data.Vector.Unboxed as VU
import qualified Data.Vector.Unboxed.Mutable as VUM
import Data.Array.Unboxed
import Data.Array.ST
import qualified Data.ByteString.Char8 as BS
import Control.Monad
import Data.List
import Data.Char

main :: IO ()
main = do
    (n,m,q) <- (\vec -> (vec VU.! 0, vec VU.! 1, vec VU.! 2)) . VU.unfoldrN 3 (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine
    vec <- VU.replicateM q $ (\vec -> (vec VU.! 0, vec VU.! 1, vec VU.! 2, vec VU.! 3)) . VU.unfoldrN 4 (BS.readInt . BS.dropWhile isSpace) <$> BS.getLine
    let all :: [[Int]]
        all = [ [x1,x2,x3,x4,x5,x6,x7,x8,x9,x10] | x1 <- [1..m], x2 <- [x1..m], x3 <- [x2..m], x4 <- [x3..m], x5 <- [x4..m], x6 <- [x5..m], x7 <- [x6..m], x8 <- [x7..m], x9 <- [x8..m], x10 <- [x9..m]]
    let solve :: [Int] -> [(Int,Int,Int,Int)] -> Int
        solve _ []      = 0
        solve xs ((a,b,c,d):ys) = if (xs !! (b-1)) - (xs !! (a-1)) == c then d+(solve xs ys) else solve xs ys
    print $ maximum [ solve xs (VU.toList vec) | xs <- map (take n) all]