import Data.List (permutations)
import Control.Applicative ((<$>))
import Data.Maybe (fromJust)
import qualified Data.Vector.Unboxed as V
import qualified Data.ByteString.Lazy.Char8 as B

judge :: V.Vector Int -> V.Vector Int -> Int
judge is t
    | V.elemIndex i1 is < V.elemIndex i2 is = s
    | otherwise                             = 0
    where
        i1 = (V.!) t 0
        i2 = (V.!) t 1
        s = (V.!) t 2

main :: IO ()
main = do
    [n, _] <- map read . words <$> getLine
    ts <- map V.fromList . map (map (fst . fromJust . B.readInt)) . map B.words . B.lines <$> B.getContents
    print $ maximum $ map (\p -> sum $ map (judge p) ts) $ map V.fromList $ permutations [0 .. n - 1]