#include<fstream>
using namespace std;
int main ()
{
    ifstream fin ("fact.in");
    ofstream fout ("fact.out");
    unsigned y , x , i , putere=1 , P , N=1;
    fin>>P;
    for(i=0;i<p;i++)
    {
        putere=putere*10;
    }
    while(x%putere!=0)
      {
        x=N*(N+1);
        N++;
      }
    fout<<x;
    fin.close ();
    fout.close ();
}