#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 (aa < c) {
        a -= c - aa;
        b += c - aa;
    }
    cout << a + min(b, d) << endl;
    return 0;
}