codeforces-1A Theatre Square

codeforces.com/problemset/problem/1/A

题意:有n*m的剧院，需要用多少a*a的石板才能铺满。（石板不能裁剪）
(1 ≤n, m, a ≤ 10^9).
 最大情况为10^18

C

#include <stdio.h>
typedef long long int64; 
int main()
{
    
    int n,m,a;
    int64 stonesX,stonesY;
    
    while(scanf("%d %d %d",&n,&m,&a)!=EOF){     
        stonesX = n > a ? (n+a-1)/a : 1;
        stonesY = m > a ? (m+a-1)/a : 1; 
        printf("%I64d\n",stonesX*stonesY); 
        
    }
    return 0; 
}