Description

John built a castle out of sand. Like all castle walls, this wall has many gun ports, and the sections between two adjacent gun ports are called "battlements." The wall has a total of $N$ ($1 < N ≤ 25000$) battlements, each with a height of $M_i$ ($1≤M_i≤10^5$).
Now, John wants to adjust the height of the battlements to a certain order of $B_i$ ($1≤B_i≤10^5$). For each unit increase in height, John needs $X$ ($1≤X≤100$) dollars; for each unit decrease, he needs $Y$ ($1≤Y≤100$) dollars. The question is: what is the minimum amount of money John needs to achieve his goal?

Input Format

The first line contains three integers $N$, $X$, and $Y$.
The next $N$ lines each contain two integers $M_i$ and $B_i$.

Output Format

A single integer representing the minimum cost.

Sample

3 6 5
3 1
1 2
1 2

11