#include<cstdio>
#include <iostream>
#include<algorithm>
#include<string>
#include<queue>
#include<vector>
#include<functional>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<numeric>

using namespace std;
typedef long long ll;
typedef pair<int, int> Pr;

int Aw, Ab, Bw, Bb, C, D;
ll ans;

int main()
{
	cin >> Aw >> Ab >> Bw >> Bb >> C >> D;

	ans = Aw;
	if (C > Ab) {
		ans -= C - Ab;
		Bw += C - Ab;
	}
	if (D < Bw) {
		ans += Bw-(Bw - D);
	}
	else
		ans += Bw;
	cout << ans << endl;
	return 0;
}