using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
 
class Program
{
    public void Proc()
    {
        Reader.IsDebug = false;
        int[] inpt = Reader.GetInt();
        
        int aW = inpt[0];
        int aB = inpt[1];
        
        inpt = Reader.GetInt();
        int bW = inpt[0];
        int bB = inpt[1];
        
        inpt = Reader.GetInt();
        int c = inpt[0];
        int d = inpt[1];
        
        if(aB > c) {
            bB += c;
            aB -= c;
        } else
        {
            bW += (c-aB);
            aW -= (c-aB);
            bB += aB;
            aB = 0;
        }
        if(bW > d) {
            aW += d;
        } else
        {
            aW += bW;
        }
        Console.WriteLine(aW);
        
    }

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


43682 82641
54647 3647
92674 64591


 
";
        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();
    }
}