In a radical publicity stunt, Gozz has decided to cover Oak Lawn with a giant PCS banner. Specifically, the banner will be made of small \(a \times a\) square banners arranged to cover the total \(x \times y\) area rectangle (oak lawn).

Help Gozz find the smallest number of square banners needed to cover the entire \(x \times y\) space.

The covered area can be larger than Oak Lawn, you cannot break the smaller banners into smaller ones and they should be placed parallel to the sides of Oak Lawn.

Input Specification

Three space-separated positive integers \(x,y\) and \(a (1 \leq x,y,a \leq 10^9)\).

Output Specification

The number of small banners needed.

Sample Input 1

8 8 4

Sample Output 1

4

Sample Input 2

10 10 3

Sample Output 2

16