size_A = gets.chomp.to_i
input_values_A = []

input_strings_A = gets.chomp.split
for i in 0..size_A-1
  input_value_A = input_strings_A[i].to_i
  input_values_A.push(input_value_A)
end


size_B = gets.chomp.to_i
input_values_B = []

input_strings_B = gets.chomp.split
for i in 0..size_B-1
  input_value_B = input_strings_B[i].to_i
  input_values_B.push(input_value_B)
end

duplicated_word_count = 0
for i in 0..size_A-1
  for j in 0..size_B-1
    if input_values_B[j]==input_values_A[i]
      duplicated_word_count += 1
    break
    end
  end
end
puts duplicated_word_count