#include <bits/stdc++.h>
#define p(s) cout<<(s)<<endl
using namespace std;

int main(){
	int Aw,Ab,Bw,Bb,C,D;
	cin>>Aw>>Ab>>Bw>>Bb>>C>>D;
	Bw+=Aw;
	Aw-=max(0,C-Ab);
	Bw-=Aw;
	Aw+=min(Bw,D);
	p(Aw);
	return 0;
}