#include <iostream>
using namespace std;

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