#include <iostream>
#include <algorithm>

#define ll long long

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);
    bw+=(c-ab);
}
 aw+=min(bw,d);
 cout<<aw<<endl;
 
 return 0;
}