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

class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;

        int whiteCount = int.Parse(Reader.ReadLine());

        int[] whiteBlocks = Reader.GetInt();

        int blackCount = int.Parse(Reader.ReadLine());

        int[] blackBlocks = Reader.GetInt();

        int maxLen = Math.Max(whiteBlocks.Max(), blackBlocks.Max());

        // 白始まり
        int currentSize = maxLen + 1;
        int ans = 0;
        List<bool> bwList = new List<bool>(new bool[] { true, false });
        bwList.ForEach((nextBlack) => {
            int result = 0;
            currentSize = maxLen + 1;
            while (currentSize > 0)
            {
                Nullable<int> tmp;
                if (nextBlack)
                {
                    tmp = blackBlocks.Max(a => a < currentSize ? a : 0);
                }
                else
                {
                    tmp = whiteBlocks.Max(a => a < currentSize ? a : 0);
                }
                nextBlack = !nextBlack;
                if (tmp == null || tmp.Value == 0)
                {
                    break;
                }
                else
                {
                    result++;
                    currentSize = tmp.Value;
                }
            }
            ans = Math.Max(ans, result);
        });
        Console.WriteLine(ans);

    }


    public class Reader
    {
        public static bool IsDebug = true;
        private static String PlainInput = @"




3
5 3 2
4
4 11 9 19



 
";
        private static System.IO.StringReader Sr = null;
        public static string ReadLine()
        {
            if (IsDebug)
            {
                if (Sr == null)
                {
                    Sr = new System.IO.StringReader(PlainInput.Trim());
                }
                return Sr.ReadLine();
            }
            else
            {
                return Console.ReadLine();
            }
        }
        public static int[] GetInt(char delimiter = ' ', bool trim = false)
        {
            string inptStr = ReadLine();
            if (trim)
            {
                inptStr = inptStr.Trim();
            }
            string[] inpt = inptStr.Split(delimiter);
            int[] ret = new int[inpt.Length];
            for (int i = 0; i < inpt.Length; i++)
            {
                ret[i] = int.Parse(inpt[i]);
            }
            return ret;
        }
    }
    static void Main()
    {
        Program prg = new Program();
        prg.Proc();
    }
}