#!/local/bin/ruby
(0..7).to_a.permutation { |a|
   h = {}
   collision = false
   (0..7).each { |x|
     y = a[x]
     collision = true if h[x+y]
     break if collision
     h[x+y] = true
   }
   next if collision
   
   h = {}
   collision = false
   (0..7).each { |x|
     y = a[x]
     collision = true if h[x-y]
     break if collision
     h[x-y] = true
   }
   next if collision
         
   puts a.join('-')
 }