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.*;

// UVa 11504

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();
		
		long first = a;
		long last = b;
		
		if (first % x != 0) {
			first += (x - a % x);
		}
		if (last % x != 0) {
			last -= b % x;
		}
		
		System.out.println((last - first) / x + 1);
	}
}