gets.to_i
w_list = gets.to_s.split(" ").map(&:to_i).sort{|a, b| b <=> a}.uniq.map{|n| ["W", n] }
gets.to_i
b_list = gets.to_s.split(" ").map(&:to_i).sort{|a, b| b <=> a}.uniq.map{|n| ["B", n] }
result_list = (w_list + b_list)
(w_list + b_list).sort{|a, b| b[1] <=> a[1]}.each_cons(2){|n1, n2| result_list.push ["WB",n1[1]] if n1[1] == n2[1]}
result_list.sort!{ |a, b| b[0].length + b[1] <=> a[0].length + a[1] }.uniq!{|n| n[1]}
#p result_list
count = 1
result_list.each_cons(2) do |n1, n2|
  #p "#{n1} #{n2}"
  if n2[0].eql? "WB"
    #p "tr"
    n2[0] = n1[0].tr("WB", "BW") 
    count += 1
  elsif !(n1[0].eql? n2[0])
    #p "count"
    count += 1
  elsif (n1[0].eql?("WB") && n2[0].eql?("WB"))
    #p "count"
    count += 1 
  end
  
end if result_list.length != 1 
p count