#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); i++)
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<vector<ll>> vvll;
const ll inf = 1e16;
const ll md = 1000000007;

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