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 [*0...N].permutation.map{|perm|
  perm.each_cons(2).map{|a, b|
    tbl[a*10+b]
  }.sum
}.max