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.

-----Sample Input-----
4 8 2

-----Sample Output-----
3

There are three integers between 4 and 8, inclusive, that are divisible by 2: 4, 6 and 8.

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