import Data.Array
import Data.List
import Control.Monad

main = do
  li <- getLine
  let (n:m:_) = map read $ words li
  cs <- forM [1..m] $ \_ -> do
    li <- getLine
    let (i1:i2:s:_) = map read $ words li
    return ((seq i1 i1,seq i2 i2),seq s s)
  print $ compute n cs

compute :: Int -> [((Int,Int),Int)] -> Int
compute n cs = maximum $ step [0..n-1] where
  ar = accumArray (+) 0 ((0,0),(n-1,n-1)) cs
  step [] = [ 0 ]
  step xs =
   [ s0 + s1
   | x <- xs
   , let xs1 = delete x xs
   , let s0 = sum [ ar ! (x,y) | y <- xs1 ]
   , s1 <- step xs1
   ]