#include<iostream>
#include<string>
#include<algorithm>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<map>
#include<vector>
using namespace std;
typedef long long int ll;

int main(){

  int Aw, Ab, Bw, Bb, C, D;
  cin >> Aw >> Ab >> Bw >> Bb >> C >> D;
  cout << Aw-max(C-Ab, 0)+min(Bw+max(C-Ab, 0), D) << endl;
  
  return 0;
}