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();	//a以上
		long b=sc.nextLong();	//b以下
		long x=sc.nextLong();	//xで割り切れる

		long num=0;	//求める個数

		if(a%x==0) num=(b/x)-(a/x)+1;
		else num=(b/x)-(a/x);

		//答えを出力
		System.out.println(num);
	}
} 