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

int aw, ab, bw, bb, c, d;
void input() { cin >> aw >> ab >> bw >> bb >> c >> d; }

void solve() {
  int tmp = min(aw, c);
  aw -= tmp;
  bw += tmp;
  aw += min(d, bw);
  cout << aw << endl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  input();
  solve();
  getchar();
}