#include <iostream>
using namespace std;
int main() {
	int Aw, Ab;
	int Bw, Bb;
	int C, D;
	cin >> Aw >> Ab >> Bw >> Bb >> C >> D;
	if (C > Ab) { Aw -= (C - Ab); Bw += (C - Ab); }
	if (D > Bw) { Aw += Bw; }
	else { Aw += D; }
	cout << Aw << endl;
	return 0;
}