#include<bits/stdc++.h>
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;
    }
    if(bw<d) aw+=bw;
    else aw+=d;
    cout << aw << endl;

    return 0;
}