#include<bits/stdc++.h>
using namespace std;
using Int = long long;
//INSERT ABOVE HERE
signed main(){
  Int aw,ab,bw,bb,c,d;
  cin>>aw>>ab>>bw>>bb>>c>>d;
  {
    Int x=min(c,ab);
    Int y=c-x;
    aw-=y;ab-=x;
    bw+=y;bb+=x;
  }
  {
    Int x=min(d,bw);
    Int y=d-x;
    bw-=x;bb-=y;
    aw+=x;ab+=y;
  }
  cout<<aw<<endl;
  return 0;
}