Problem Statement

There are $N$ towns on a line running east-west. The towns are numbered $1$ through $N$, in order from west to east. Each point on the line has a one-dimensional coordinate, and a point that is farther east has a greater coordinate value. The coordinate of town $i$ is $X_i$.

You are now at town $1$, and you want to visit all the other towns. You have two ways to travel:

• Walk on the line. Your fatigue level increases by $A$ each time you travel a distance of $1$, regardless of direction.
• Teleport to any location of your choice. Your fatigue level increases by $B$, regardless of the distance covered.

Find the minimum possible total increase of your fatigue level when you visit all the towns in these two ways.

Constraints

• All input values are integers.
• $2≤N≤10^5$
• $1≤X_i≤10^9$
• For all $i(1≤i≤N-1)$, $X_i<X_{i+1}$.
• $1≤A≤10^9$
• $1≤B≤10^9$

Input

The input is given from Standard Input in the following format:

N A B
X_1 X_2 ... X_N

Output

Print the minimum possible total increase of your fatigue level when you visit all the towns.