#include<iostream>
#include<vector>

int main() {
	std::vector<std::pair<int, int> > bag;

	for (int i = 0; i < 2; i++)
	{
		int white, black;
		std::cin >> white >> black;
		bag.push_back(std::make_pair(white, black));
	}

	int c, d;
	std::cin >> c >> d;

	if (c <= bag[0].second) {
		bag[1].second += c;
		bag[0].second -= c;
	}
	else {
		bag[1].second += bag[0].second;
		c -= bag[0].second;
		bag[1].first += c;
		bag[0].first -= c;
	}

	if (d <= bag[1].first) {
		bag[0].first += d;
	}
	else {
		bag[0].first += bag[1].first;
	}

	std::cout << bag[0].first << std::endl;

	return 0;
}