#include<iostream>
#include<algorithm>

using namespace std;

#define NMAX 100000

int main(){

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

	cin>>Aw>>Ab;
	cin>>Bw>>Bb;
	cin>>C>>D;

	if(Ab<C) Aw-=(C-Ab),Bw+=(C-Ab),Bb+=Ab;
	else Bb+=C,Ab-=C;
	if(Bw<=D) Aw+=Bw,Ab+=(D-Bw),Bw=0,Bb-=(D-Bb);
	else Aw+=D,Bw-=D;

	cout<<Aw<<endl;

}