Problem Statement

You are given nonnegative integers $a$ and $b$ ($a ≤ b$), and a positive integer $x$. Among the integers between $a$ and $b$, inclusive, how many are divisible by $x$?

Constraints

• $0 ≤ a ≤ b ≤ 10^{18}$
• $1 ≤ x ≤ 10^{18}$

Input

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

a b x

Output

Print the number of the integers between $a$ and $b$, inclusive, that are divisible by $x$.