#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<queue>
#include<map>
#include<math.h>
#include<iomanip>
#include<set>
#include<numeric>
#include<cstring>
#include<cstdio>
#include<functional>
#include<bitset>
#include<limits.h>
#include<cassert>
#include<iterator>
#include<complex>
#include<stack>
using namespace std;
#define lint long long int
/*
vector<char>al(26);
al = {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};
vector<char>AL(26);
AL = {'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
*/

int main() {
	int AW, AB, BW, BB, C, D;
	cin >> AW >> AB >> BW >> BB >> C >> D;
	if (AB >= C) {
		AB -= C;
		BB += C;
	}
	else if (AB < C) {
		BB += AB;
		BW += C - AB;
		AW -= (C - AB);
		AB -= AB;
	}
	if (D <= BW) {
		BW -= D;
		AW += D;
	}
	else if (D > BW) {
		AW += BW;
		AB += (D - BW);
		BB -= (D - BW);
		BW -= BW;
	}
	cout << AW << endl;
}