#include<iostream>
using namespace std;

int aw, ab;
int bw, bb;
int c, d;

int main() {
	int i;
	cin >> aw >> ab;
	cin >> bw >> bb;
	cin >> c >> d;
	
	int wcnt, bcnt;
	//Aのwhiteは極力残す
	bcnt = min(ab, c);
	wcnt = c - bcnt;
	bw += wcnt;
	bb += bcnt;
	aw -= wcnt;
	ab -= bcnt;
	//cout << aw << " " << ab << " " << bw << " " << bb << endl;
	//Bのwhiteは極力Aに移す
	wcnt = min(bw, d);
	bcnt = d - wcnt;
	aw += wcnt;
	ab += bcnt;
	bw -= wcnt;
	bb -= bcnt;
	//cout << aw << " " << ab << " " << bw << " " << bb << endl;
	cout << aw << endl;
	return 0;
}