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 s = new Scanner(System.in);
		long a = s.nextLong(), b=s.nextLong(), x=s.nextLong();
		
		long start=0, end=0, ans=0;
		if (a%x==0) {
			start = a;
		}else {
			start = (x - a%x)+a;
		}
		end = b - (b%x);
		
		if (start<=b && end>=a) {
			start /= x;
			end /= x;
			ans = end-start+1;
		}
		
		System.out.println(ans);
		s.close();
	}
}