#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<map>
#include<queue>
#include<string>
#include<sstream>
#include<cmath>
using namespace std;

int main(){

  int aw, ab, bw, bb, c, d;
  cin >> aw >> ab >> bw >> bb >> c >> d;

  if( ab < c ){
    aw -= (c - ab);
    bb += ab;
    bw += (c - ab);
    ab = 0;
  }else{
    ab -= c;
    bb += c;
  }

  if( bw < d ){
    bb -= (d - bw);
    aw += bw;
    ab += (d - bw);
    bw = 0;
  }else{
    bw -= d;
    aw += d;
  }

  cout << aw << endl;

  return 0;
}