H. Packing circles
time limit per test
2 seconds
memory limit per test
64 megabytes
input
standard input
output
standard output

You are given rectangle dimensions (W - width, H - height) and circle diameter D. How many circles can you fit inside that rectangle? Circles must be placed in rows parallel to the bottom. Each row must have the same amount of circles. Each pair of consecutive rows must have the same distance between them. A row is defined by a horizontal line. Circle belongs to a row if its center point lies on that line.

Input

A single line contains 3 integers W, H and D. (1 ≤ W, H, D ≤ 106)

Output

A single integer - the maximal amount of circles that can fit inside the rectangle with given restrictions.

Examples
Input
2 2 2
Output
1
Input
2 2 1
Output
4