#include <vector>
#include <string>
#include <algorithm>
#include <numeric>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <utility>
#include <list>
#include <functional>
#include <queue>
#include <map>
#include <iterator>
#include <iomanip>
#include <complex>
using namespace std;

using ull = unsigned long long;
using ll = long long;


int main()
{
  int aw,ab;
  int bw,bb;
  int c,d;
  cin >> aw >> ab >> bw >> bb >> c >> d;

  if(ab >= c)
  {
    aw += min(bw,d);
  }
  else
  {
    bw += min(aw,c-ab);
    aw -= c-ab;
    aw += min(bw,d);
  }

  cout << aw << endl;

}