#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

int main() {
  int aw, ab, bw, bb, c, d;
  cin >> aw >> ab >> bw >> bb >> c >> d;
  int t = max(0, c - ab);
  int ans = aw - t + min(d, t + bw);
  cout << ans << endl;
  return 0;
}