50 50 50 50
 49 49 4 1
 48 50 12 11
 5 7 1 10
 1 50 50 50
 5 7 1 4
 32 4 17 3
 1 50 1 50
 50 1 1 1
 32 31 10 9
 5 7 4 1
 49 49 3 3
 50 49 1 2
 50 48 3 1
 50 1 1 50
 5 7 10 10
 1 1 1 1
 49 50 11 12

Second
 Second
 Second
 Second
 Second
 Second
 First
 Second
 First
 First
 Second
 Second
 First
 First
 First
 Second
 Second
 Second

#include <bits/stdc++.h>
int main() {
  int m, n, a, y, x, res;
  scanf("%d", &m);
  scanf("%d", &n);
  scanf("%d", &a);
  y = m / a;
  x = n / a;
  if (m % a != 0) y = y + 1;
  if (n % a != 0) x = x + 1;
  res = y * x;
  printf("%d", res);
}
