using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            int count = 0, j, n, m, t, i;
            n = int.Parse(Console.ReadLine());
            int[] p_dat = new int[n];

            for (i = 0; i < n; i++)
            {
                p_dat[i] = int.Parse(Console.ReadLine());

            }
            m = int.Parse(Console.ReadLine());
            int[] s_dat = new int[m];
            for (i = 0; i < m; i++)
            {
                s_dat[i] = int.Parse(Console.ReadLine());
            }
            for (i = 0; i < n - 1; i++)
            {
                if (p_dat[i] == p_dat[i + 1])
                {
                    p_dat[i] = p_dat[i + 1];
                    i--;
                    n--;
                }

            }

            p_dat = p_dat.Distinct().ToArray();

            count = 0;
            for (i = 0; i < m; i++)
            {
                for (j = 0; j < n; j++)
                {
                    if (s_dat[i] == p_dat[j])
                    {
                        count++;
                    }
                }
            }
            Console.WriteLine(count);
            //Console.ReadKey();
        }
    }
}