#include<iostream>
#include<algorithm>
using namespace std;
int main(){
	int Aw, Ab, Bw, Bb, C, D;
	cin >> Aw >> Ab >> Bw >> Bb >> C >> D;
	cout << Aw - max(C - Ab, 0) + min(Bw + max(C - Ab, 0), D) << endl;
	return 0;
}