#include <iostream>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <limits>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <complex>

using namespace std;

#define INF (INT_MAX/3)
#define PI (2*acos(0.0))
#define EPS (1e-8)

typedef long long ll;
typedef unsigned long long ull;

int main(){
  ios_base::sync_with_stdio(0);
  int Aw, Ab, Bw, Bb;
  int C,D;
  cin >> Aw >> Ab >> Bw >> Bb;
  cin >> C >> D;
  Aw -= max(C - Ab, 0); Bw += max(C - Ab, 0);
  if(D > Bw) Aw += Bw;
  else Aw += D;
  cout << Aw << endl;
  return 0;
}