Codeforces 1A-Theatre Square(水)

A. Theatre Square

time limit per test

2 seconds

memory limit per test

64 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.

Sample test(s)

input

6 6 4

output

4

周末的手速赛？。。没做 周末一直在做网络赛。。回来补一下

题意：给n*m的矩形，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。。太水了，不说了

#include 
#include 
#include 
#include 
#include 
#include 
#include 
using namespace std;
const int INF=0x3f3f3f3f;
#define LL long long
int main()
{
	int n,m,a;
	while(cin>>n>>m>>a){
		LL x=n%a==0?n/a:n/a+1;
		LL y=m%a==0?m/a:m/a+1;
		cout<