#include<iostream>
using namespace std;

int main() {
    int aw, ab, bw, bb, c, d;
    cin >> aw >> ab >> bw >> bb >> c >> d;
    if (ab >= c) {
        ab -= c;
        bb += c;
    }
    else {
        aw -= (c - ab);
        bw += (c - ab);
        bb += ab;
        ab = 0;
    }
    if (bw >= d) {
        aw += d;
        bw -= d;
    }
    else {
        bb -= (d - bw);
        ab += (d - bw);
        aw += bw;
        bw = 0;
    }
    cout << aw << endl;
}