#include <iostream>
#include <cmath>
#include <string>
#include <vector>
#include <map>
#include <algorithm>

using namespace std;

int main() {
	int aWhite, aBlack;
	int bWhite, bBlack;
	int c, d;

	cin >> aWhite >> aBlack >> bWhite >> bBlack >> c >> d;

	for (int i = 0; i < c; i++) {
		if (aBlack > 0) {
			aBlack--;
			bBlack++;
		} else  {
			aWhite--;
			bWhite++;
		}
	}

	for (int j = 0; j < d; j++) {
		if (bWhite > 0) {
			bWhite--;
			aWhite++;
		} else {
			bBlack--;
			aBlack++;
		}
	}
	cout << aWhite << endl;
	return 0;
}