/*#include <fstream>

using namespace std;

int main()
{
    unsigned n,i,x,y;
    ifstream fin("euclid2.in");
    ofstream fout("euclid2.out");
    fin>>n;
    for(i=1;i<=n;i++)
    {
        fin>>x>>y;
        {
            while(x!=y)
            {
            if(x>y)
                x=x-y;
            else
                y=y-x;
            }
        fout<<x<<'\n';
        }
    }

    fin.close();
    fout.close();
    return 0;

}*/

#include<fstream>
using namespace std;
int main()
{

    unsigned p, i=0,nr=0,r;
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    fin>>p;
    while(i%5==0)
		{
			{ nr++;
			  r=i;
			  r=r/5;
			}
			i=i+5;
		}
	    if(nr==p)
		   fout<<i;
    fin.close();
    fout.close();
	return 0;

}