#!/usr/bin/ruby

# Facebook's 'Gattaca' puzzle.
# tom.luo@mgail.com


class Prediction
   attr_accessor :start, :stop, :score, :highest_score
   def initialize(start,stop,score)
       @start=start
       @stop=stop
       @score=score
       @highest_score=0
   end
   
   def SetHighestScore(score)
      @highest_score=score
   end

  
end



def HighestScore(list)
last=list.size-1

global_max = list[last].highest_score

temp_list=[]
last.downto 0 do |i|
   max = 0
   i_seq = list[i]
   
   # temp_list.uniq!
   temp_list.each do |x| 
#   k+=1 
 #  puts k if k>1 
#   puts i_seq.stop.to_s + " " + x.start.to_s
   if i_seq.stop < x.start and max < x.highest_score then 
     max = x.highest_score
   break 
end
   end
    i_seq.SetHighestScore(i_seq.score + max)
    if temp_list.empty?
       temp_list[0]=i_seq
     else
       if i_seq.highest_score >= temp_list[0].highest_score then
          temp_list = [i_seq].concat(temp_list)
       else  
          temp_list.push(i_seq)
       end
     end
    global_max = i_seq.highest_score if i_seq.highest_score > global_max
end
global_max
end


# Main
file_name=ARGV[0]

file=File.open(file_name,"r")
lines = file.readlines

# ----------------------------------------------------
# collect the genes 
# ----------------------------------------------------
predictions = []
lines.each do |line|
   fields=line.split()
   if fields.size==3 
     start=fields[0].to_i
     stop=fields[1].to_i
     score=fields[2].to_i
     predictions << Prediction.new(start,stop,score)
#     predictions << Prediction.new(fields[0],fields[1],fields[2])
  end
end

# puts predictions.size
# predictions.sort! {|x,y| x.start <=> y.start}
 predictions = predictions.sort_by { |a|  a.start }
# predictions.each {|p| puts "#{p.start} #{p.stop} #{p.score}"}
 puts "#{HighestScore(predictions)}\n"
# predictions.each {|p| puts "#{p.start} #{p.stop} #{p.score} #{p.highest_score}"}
# -----------------------------------------