codeforces 1A

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

 

很简单的一道题，我竟然想了很久，绕了半天才绕回来。。。

 

 

直接贴代码：

 

#include<iostream>
using namespace std;
int main(){
    __int64 n,m,a;
    cin>>n>>m>>a;
    __int64 sum=0;
    int flag1=0;
    int flag2=0;
    if(n%a)
         flag1=1;
    if(m%a)
         flag2=1;      
    sum=(n/a+flag1)*(m/a+flag2);
    cout<<sum<<endl;
    cin>>n;
    return 0;
}