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.

Examples

Input

4 8 2


Output

3


Input

0 5 1


Output

6


Input

9 9 2


Output

0


Input

1 1000000000000000000 3


Output

333333333333333333
#!/usr/bin/python

import sys

def main(argv):
    for line in sys.stdin:
        a, b, x = line.rstrip("\n").split(" ", 3)
        a = int(a)
        b = int(b)
        x = int(x)

        start_index, start_reminder = divmod(a, x)
        end_index, end_reminder = divmod(b, x)

        result = end_index - start_index
        if a == 0 or start_reminder == 0:
            result += 1
        print result

if __name__ == "__main__":
    main(sys.argv)