#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
//#include <atcoder/all>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
using ll = long long;
using namespace std;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

int main(){
  ll W1,B1,W2,B2,C,D; cin >> W1 >> B1 >> W2 >> B2 >> C >> D;
  ll left = C;
  ll rm = min(left,B1);
  B1-=rm;B2+=rm;
  left-=rm;
  if(left){
    W1-=left;W2+=left;
    left=0;
  }
  left = D;
  rm = min(left,W2);
  W2-=rm;W1+=rm;
  cout << W1 << endl;
  return 0;
}