int a, k, b, m, x;
    cin >> a >> k >> b >> m >> x;
    int l = -1, r = 1e18;
    while(r - l > 1) {
        int mid = (r + l) >> 1;
        int cnt = (mid * a - (mid / k) * a) + (mid * b - (mid / m) * b);
        if(cnt >= x) {
//            cerr << mid << " " << cnt << '\n';
            r = mid;
        }
        else {
            l = mid;
        }
    }
    cout << r;