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.*;
import java.awt.*;
import static java.lang.System.*;
import static java.lang.Math.*;
//Loopで使う文字列の長さは固定！
//intで大丈夫？オーバーフローしない？
//Loop回数は本当に10⁹以内になってる？Loopは回る？？
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(in);
        long a=sc.nextLong();
        long b=sc.nextLong();
        long x=sc.nextLong();
        out.println(-(a+x-1)/x+(b+1+x-1)/x);
    }
}
