//問題勘違いしてたよ（バンバン！）汚いのはそのせいだからね！
#include <iostream>
#include <algorithm>
#include <cstring>
#include <climits>
#include <vector>
using namespace std;
typedef unsigned long long ULL;
typedef long long LL;

int main()
{
	int Aw[3], Ab[3], Bw[3], Bb[3], C, D;
	cin >> Aw[0] >> Ab[0] >> Bw[0] >> Bb[0] >> C >> D;

	if (Ab[0] >= C)
	{
		Aw[1] = Aw[0];
		Bw[1] = Bw[0];
		Ab[1] = Ab[0] - C;
		Bb[1] = Bb[0] + C;
	}
	else
	{
		Aw[1] = Aw[0] - C + Ab[0];
		Bw[1] = Bw[0] + C - Ab[0];
		Ab[1] = 0;
		Bb[1] = Bb[0] + Ab[0];
	}

	if (Bw[1] >= D)
		Aw[2] = Aw[1] + D;
	else
		Aw[2] = Aw[1] + Bw[1];

	cout << Aw[2];

	return 0;
}