Cacher is the code snippet organizer for pro developers

n=gets.to_i
@g=Array.new(n){[]}
(n-1).times do |i|
  b=gets.to_i
  @g[b-1]<< i+1
end

def rec i
  if @g[i].size()==0
    1
  else
    s=[]
    @g[i].each do |j|
        s<< rec(j)
    end
    s.max+s.min+1
  end
end

puts rec 0