#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> P;
typedef pair<int,pair<int,int>> PP;
typedef long long ll;

const double EPS = 1e-8;
const int INF = 1e9;
const int MOD = 1e9+7;

int dy[] = {0,1,0,-1};
int dx[] = {1,0,-1,0};

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

	int c,d;
	cin >> c >> d;

	if(ab < c){
		bb += ab;
		bw += c - ab;
		aw -= c - ab;
	}else{
		bb += min(c,ab);
	}

	if(bw < d){
		aw += bw;
	}else{
		aw += min(bw,d);
	}
	cout << aw << endl;
	return 0;
}