#include <bits/stdc++.h>
#define PI 3.14159265359
#define NIL -1
using namespace std;
const int64_t MOD = 1e9 + 7;

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

	if (C > Ab) {
		Aw -= C - Ab;
		Bw += C - Ab;
	}

	if (D < Bw) {
		Aw += D;
	}
	else {
		Aw += Bw;
	}

	cout << Aw << endl;
}