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

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long a = in.nextLong();
        long b = in.nextLong();
        long x = in.nextLong();


        System.out.println(f(b, x) - f(a - 1, x));
    }

    private static long f(long n, long x) {
        if (n >= 0) {
            return n / x + 1;
        }
        return 0;
    }
}
