#include <bits/stdc++.h>
using namespace std;
int main() {
    // Input
    int Aw, Ab, Bw, Bb, C, D;
    cin >> Aw >> Ab >> Bw >> Bb >> C >> D;

    // Simulation
    int pick_b = min(Ab, C);
    int pick_w = C - pick_b;
    Ab -= pick_b;
    Bb += pick_b;
    Aw -= pick_w;
    Bw += pick_w;
    int pick_w_return = min(Bw, D);
    int pick_b_return = D - pick_w_return;
    Ab += pick_b_return;
    Bb -= pick_b_return;
    Aw += pick_w_return;
    Bw -= pick_w_return;

    // Output
    cout << Aw << endl;
}