#include <iostream>
using namespace std;
int main(){
	int Aw, Ab;
	cin >> Aw >> Ab;
	int Bw, Bb;
	cin >> Bw >> Bb;
	int C, D;
	cin >> C >> D;
	int ans = 0;
	for (int w = 0; w <= Aw; w++){
		int b = C - w;
		if (0 <= b && b <= Ab){
			int Aw2 = Aw - w;
			int Ab2 = Ab - b;
			int Bw2 = Bw + w;
			int Bb2 = Bb + b;
			ans = max(ans, Aw2 + min(Bw2, D));
		}
	}
	cout << ans << endl;
}