1A - Theatre Square

include <bits/stdc++.h>

using namespace std; int main(){ long long n,m,a,ans = 1; cin>>n>>m>>a; if(n%a!=0) { ans*=(n/a+1); } else { ans*=n/a; } if(m%a!=0) { ans*=(m/a+1); } else { ans*=m/a; } cout<<ans; }