#include <bits/stdc++.h>

using namespace std;

int main()
{
  int Aw, Ab;
  int Bw, Bb;
  int C, D;

  cin >> Aw >> Ab;
  cin >> Bw >> Bb;
  cin >> C >> D;

  int myon = min(Ab, C);
  C -= myon;
  Bb += myon;
  Bw += C;
  Aw -= C;

  cout << Aw + min(Bw, D) << endl;
}