Codeforce 1A Theatre Square （每日一水练读题练手速）No.8

Theatre Square

传送
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

6 6 4

output

4

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题目大意：

n×m的矩阵能由几个a×a的矩阵覆盖

做法：

长和宽都覆盖就可以了
ans=覆盖长需要的个数*覆盖宽需要的个数

代码：

#include<iostream>
using namespace std;
long long n,m,p,a,b,ans;
int main(){
	while(cin>>n>>m>>p){
		if(n%p==0) a=n/p;
		else a=(n/p)+1;
		if(m%p==0) b=m/p;
		else b=(m/p)+1;
		ans=a*b;
		cout<<ans<<endl;
	}
}