#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>

using namespace std;

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

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

	int pick = max(0, c - ab);
	aw -= pick;
	bw += pick;

	pick = min(bw, d);
	aw += pick;

	cout << aw << endl;
	return 0;
}