#include <iostream>
#include <algorithm>
using namespace std;

int main(){
	int a1, a2, b1, b2, c, d;
	cin>>a1>>a2>>b1>>b2>>c>>d;
	int cc = max(0, c-a2);
	a1 -= cc;
	b1 += cc;
	a1 += min(b1, d);
	cout<<a1<<endl;
	return 0;
}