#include <iostream>
using namespace std;


int main()
{
	int aw,ab,bw,bb,c,d;
	cin>>aw>>ab>>bw>>bb>>c>>d;

	if (ab < c){
		aw -= (c - ab);
		bw += (c - ab);
	}
	if (bw < d){
		aw += bw ;
	}else{
		aw += d;
	}

	cout<<aw<<endl;
	return 0;
}