gets
m=t=0
l=$<.map{|s|s.split.map &:to_i}.sort_by{|e|t+=v=e[2];-v}
[*0...$_.to_i].permutation.map{|a|s=t;l.all?{|e|x,y,v=*e;a.index(y)<a.index(x)&&s-=v;s>m};m<s&&m=s}
p m