#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <map>
#include <set>
#include <list>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <iomanip>
#include <functional>

#define SIZE 1005
#define INF 100000000
#define ll long long
#define FD(d) fixed << setprecision(d)
#define MOD 1000000007
     
using namespace std;
 
#define ll long long
 
typedef pair<int, int> Pa;

int main()
{
	int aw, ab;
	int bw, bb;
	int c, d;
	int res;
	int tmp;

	cin >> aw >> ab;
	cin >> bw >> bb;
	cin >> c  >> d;

	tmp = max(0, c - ab);
	res = aw - tmp + min(d, tmp + bw);

	cout << res << endl;

	return (0);
}