#include <algorithm>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#define p(s) cout<<(s)<<endl
#define REP(i,n,N) for(int i=n;i<N;i++)
#define RREP(i,n,N) for(int i=N-1;i>=n;i--)
#define CK(n,a,b) ((a)<=(n)&&(n)<(b))
#define F first
#define S second
typedef long long ll;
using namespace std;
const int inf = 1e9;

int Aw ,Ab ,Bw ,Bb;
int C,D;
int main(){
    cin>>Aw>>Ab>>Bw>>Bb>>C>>D;
    Aw -= max(0, C-Ab);
    Bw += max(0, C-Ab);
    Aw += min(D,Bw);
    p(Aw);
    return 0;
}