#include <cstdio>
#include <cstdlib>
#include <iostream>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <cstring>

typedef long long ll;
using namespace std;

#define mod 1000000007
#define INF 1000000000 //(int)1e9
#define LLINF 2000000000000000000 //(ll)2e18
#define PI  3.1415926536

#define SIZE 100000

int main(){
    int aw,ab,bw,bb,c,d;
    int s;
    
    cin >> aw >> ab >> bw >> bb >> c >> d;
    
    s = ab;
    aw-=max(0,c-s);
    bw+=max(0,c-s);
    ab-=min(c,s);
    bb+=min(c,s);
    
    s = bw;
    bb-=max(0,c-s);
    ab+=max(0,c-s);
    bw-=min(d,s);
    aw+=min(d,s);
    
    cout << aw << endl;
    
    return 0;
}