#include <iostream>
using namespace std;

int main()
{
    int aw,ab,bw,bb,c,d;
    cin >> aw >> ab >> bw >> bb >> c >> d;

    if(c > ab){
        aw -= c - ab;
        bw += c - ab;
    }
    
    cout << (d > bw ? aw + bw : aw + d) << endl;

    return 0;
}