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 sc=new Scanner(System.in);
		
		long a=sc.nextLong();
		long b=sc.nextLong();
		long x=sc.nextLong();
		
		long result=func(b,x)-func(a-1,x);
		
		System.out.println(result);
		
		
		sc.close();


	}

	public static long func(long n,long x) {
		
		if(n>=0) {
			return n/x+1;
		}else {
			return 0;
		}
		
	}

}

