Problem Solving

TheatreSquare.cpp

#include <iostream>

using namespace std;

int main() {

    long n, m, a, flagstones;
    cin >> n >> m >> a;
    if (n % a == 0 && m % a == 0)
            flagstones = (n / a) * (m / a);
        else if (n % a != 0 && m % a == 0)
            flagstones = ((n / a) + 1) * (m / a);
        else if (n % a == 0 && m % a != 0)
            flagstones = (n / a) * ((m / a) + 1);
        else
            flagstones = ((n / a) + 1) * ((m / a) + 1);
        cout << flagstones << endl;

    return 0;
}