#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
	int Aw, Ab;
	int Bw, Bb;
	int Cw, Cb, C;
	int Dw/*, Db */, D;

	cin >> Aw >> Ab;
	cin >> Bw >> Bb;
	cin >> C >> D;

	Cb = min(C, Ab);
	Cw = C - Cb;
	
	Aw -= Cw;
	//Ab -= Cb;

	Bw += Cw;
	//Bb += Cb;
	
	Dw = min(D, Bw);
	//Db = D - Dw;
	Aw += Dw;
	//Ab += Db;

	cout << Aw << endl;

	return 0;
}