#include <bits/stdc++.h>
using namespace std;

int main(){
    int Aw, Ab, Bw, Bb, C, D;
    cin >> Aw >> Ab >> Bw >> Bb >> C >> D;
    int e = max(0, C - Ab);
    Aw -= e;
    Bw += e;
    Aw += min(Bw, D);
    cout << Aw << "\n";
    return 0;
}