1A .Theatre Square

水题：

题目链接：http://codeforces.com/problemset/problem/1/A

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int main()
{
    long long m,n,a;
    scanf("%lld%lld%lld",&m,&n,&a);
    long long s1=m/a;
    if(m%a!=0)
        s1++;
    long long s2=n/a;
    if(n%a!=0)
        s2++;
    printf("%lld\n",s1*s2);

    return 0;
}