CodeForces-1A Theatre Square【水题】

 

A. Theatre Square

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Theatre Square in the capital city of Berland has a rectangular shape with the size n × m meters. On the occasion of the city's anniversary, a decision was taken to pave the Square with square granite flagstones. Each flagstone is of the size a × a.

What is the least number of flagstones needed to pave the Square? It's allowed to cover the surface larger than the Theatre Square, but the Square has to be covered. It's not allowed to break the flagstones. The sides of flagstones should be parallel to the sides of the Square.

Input

The input contains three positive integer numbers in the first line: n,  m and a (1 ≤  n, m, a ≤ 109).

Output

Write the needed number of flagstones.

Examples

input

Copy

6 6 4

output

4

 

 

 

问题链接：CodeForces-1A Theatre Square

问题简述：

  给n*m的矩形和边长为a的正方形，求最少需要多少块正方形可以铺满矩形。

问题分析：

  本题的关键是如何取整，一个典型的向上取整的问题。

程序说明：（略）

题记：用表达式进行向上取整计算才是正道！

参考链接：（略）

 

AC的C++语言程序如下：

/* CodeForces-1A Theatre Square */

#include 

using namespace std;

int main()
{
    long long n, m, a;

    while(cin >> n >> m >> a)
        cout << ((n + a - 1) / a ) * ((m + a - 1) / a) << endl;

    return 0;
}