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.*;

public class Main{
	public static void main(String[] args){
    	Scanner sc = new Scanner(System.in);
      	long a = sc.nextLong();
      	long b = sc.nextLong();
      	long x = sc.nextLong();
      
      	long fb = (b / x) + 1;
 		long fa = 0;
      	if(a - 1 != -1){
          	a = a - 1;
        	fa = (a / x) + 1;
        }
      	System.out.println(fb - fa);
    }
}