Problems
Mountain View
Mountain View
Kozak Vus is a very athletic boy, so he likes mountaineering. Therefore, this winter he decided to go to the mountains (unfortunately, he did not say where).
There are a total of $n$ separate mountain peaks located along a straight line, the $i$th peak has a height of $a_i$ meters and a beauty of $b_i$. Cossack Vus does the following: he climbs one of the mountains, looks left and right, after which he sees some other mountains. Cossack Vus can see the $i$th mountain if there are no mountains \textbf{greater than or equal to} $a_i$ meters high between the mountain where he is and the $i$th mountain. Cossack Vus also sees the mountain he climbed.
Kozak Vus set two parameters for himself: $x$ and $y$. If he climbs $1$ meter, his mood decreases by $x$ units, and if he sees a mountain with $t$ beauty, then his mood increases by $ty$ units. Initially, the mood of Cossack Mustache is $0$.
Find the maximum possible mood of Cossack Mustache after climbing one of the mountains.
Note that Cossack Mustache \textbf{needs} to climb some mountain.
\InputFile
The first line contains a single integer $n$ ($1 \leq n \leq 10^6$)~--- the number of mountains.
Each of the following $n$ lines contains two integers $a_i$ and $b_i$ ($1 \leq a_i, b_i \leq 1000$)~--- the height and beauty of the $i$ mountain.
The last line contains two integers $x$ and $y$ ($1 \leq x, y \leq 1000$).
\OutputFile
Derive a single number --- the maximum possible mood of Cossack Mustache after climbing one of the mountains.
Input example #1
6 5 3 1 5 4 5 3 2 3 2 5 1 1 2
Output example #1
28
Input example #2
1 5 5 1 2
Output example #2
5
Input example #3
3 1000 1 1000 1 1000 1 1000 1
Output example #3
-999997