E=Hash.new 9e9
$<.map{|s|M||=s.to_i-1;*f,c=s.split.map &:to_i;E[f.rotate]=E[f]=E[$.-2]=c}
(T=*0..M).product(T,T){|k,i,j|E[x=[i,j]]=[E[x],E[[k,i]]+E[[k,j]]].min}
p [*1...M].permutation(2).map{|i,j|E[i]+E[j]+E[[0,i]]+E[[i,j]]+E[[j,M]]}.min