N, M = gets.split.map &:to_i
tbl = [0]*100
$<.map{|s|
  a, b, score = s.split.map &:to_i
  tbl[a*10+b] = score
}
p (R=*0...N).permutation.map{|perm|
  R.map{|i|
    (i...N).map{|j|
      tbl[perm[i]*10+perm[j]]
    }.sum
  }.sum
}.max