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
// In the name of Allah the Most Merciful. 

import java.util.*;
import java.math.*;

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