The ACM-ICPC World Finals are over! Which team came out on top? Why,
only our favourite team - everyone's favourite team - the most
deserving, lovable, courteous, powerful, flawless, successful team that
has ever existed. Who else?
It's time to celebrate, and what better way is there to celebrate than
by eating cake? The contest organizers have bought
cakes (conveniently numbered
) - however, ever
generous, The Team will only eat cake 1, leaving the rest for the other,
inferior teams. They will need their cake to be as tasty as possible,
though. To help with this,
globs of icing are
available, which will be distributed among the cakes. Icing is always
used in whole globs.
The cakes are arranged in a somewhat strange way - piled on top of one
another. Cake 1 is directly on top of a table, while every other cake
(for
) is directly on top of cake
.
is
considered to have a value of 0. Note that there may be multiple cakes
on top of a single cake, and that the entire structure obeys the laws of
physics (no cake is on top of itself, and no cakes are floating).
Now, the tastiness of any cake
is determined by the formula
.
and
are simply properties of cake
, which depend on
its size, shape, weight, temperature, fluffiness, and so on.
is the
number of globs of icing that are chosen to be applied to cake
. If
there are no cakes on top of cake
,
- otherwise,
is the minimal tastiness of any cake directly on top of cake
. No
cake will ever be capable of achieving a tastiness value larger than
, no matter how the icing is distributed.
The members of The Team have already, of course, determined how the
available icing could be optimally applied to the mountain of cakes to
maximize the tastiness of their cake (cake 1). However, the contest
organizers are the ones who will actually be distributing the icing, and
they had better hope they get it right! Can you help them determine how
tasty cake 1 should be? You don't want to know what The Team will do if
their celebration isn't perfect…
Input Specification
First line: 2 integers,
and 
Next
lines: 3 integers,
,
, and
, for 
Output Specification
1 integer, the maximal tastiness of cake 1, after all of the icing has
been used.
Sample Input
Copy
3 2
0 5 1
1 3 4
1 2 6
Sample Output
Copy
12
Explanation of Sample
The optimal icing distribution is 1 glob each on cakes 2 and 3. This
gives cake 2 a tastiness of
, and cake 3 a tastiness of
. Since both of these cakes are on top of cake 1, it
then has a tastiness of
. No other icing
distribution yields a higher tastiness for cake 1.
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