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(),b=sc.nextLong(),x=sc.nextLong();
		if(a==0) {
			System.out.println((long)(b/x)+1);
		}else if(a==1){
			System.out.println((long)(b/x));
		}else {
			System.out.println((long)(b/x)-(long)((a-1)/x));
		}


	}
	public static int sample(int n) {
		return n;
	}

}
