def amida(prob)
  prob.split("\n").inject do |r,l|
    l.split(//).each_with_index do |e,i|
      next unless e=='-'
      r[i-1..i+1]=r[i-1..i+1].reverse
    end
    r
  end
end


prob=<<-EOD
A B C D E
| | |-| |
|-| | |-|
| |-| |-|
|-| |-| |
|-| | | |
EOD

puts prob
puts amida(prob)