CodeForces 1A Theatre Square

//CodeForces 1A Theatre Square
//http://codeforces.com/problemset/problem/1/A
/*
* 题意:
* a*a的方块铺满n*m的地，问需要多少块
* 思路:
* 直接模拟即可
* author liweijie
*/
#include <iostream>
#include <cstdio>

using namespace std;

int n,m,a;

int main()
{
while(scanf("%d %d %d",&n,&m,&a)!=EOF)
{
int cn = n/a;
if (n%a!=0) cn++;
int cm = m/a;
if (m%a!=0) cm++;
__int64 ans=cm;
ans *= cn;
printf("%I64d\n",ans);
}
return 0;
}