require 'set'

def cons_seq(arr)
  continious_sequence = 1
  all_cont_seq = Set.new

  arr.sort!.uniq!.each_with_index do |el, i|
    if el + 1 == arr[i + 1]
      continious_sequence += 1
    else
      all_cont_seq << continious_sequence
      continious_sequence = 1
    end
  end

  all_cont_seq.max
end

arr = [1,92,5,47,3,4,5,2,89,56,90,23,91,24,4,92]

puts cons_seq(arr)