#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int main() {
    int a, aa, b, bb, c, d;
    cin>>a>>aa>>b>>bb>>c>>d;
    if (a >= c) {
        a -= c;
        b += c;
    } else {
        aa -= c - a;
        bb += c - a;
        b += a;
        a = 0;
    }
    cout << a + min(b, d) << endl;
    return 0;
}