#include <fstream.h>

ifstream fin("fact.in");
ofstream fout("fact.out");
long n, i, p, d5=0,nr;
int main()
{   fin>>p;
    if (p==0) fout<<1<<"\n";
	else
	if (p==1) fout<<5<<"\n";
	else
	{	
		
    for (i=5; ; i=i+5)
	{nr=i;
	 while (nr%5==0)
		 {d5++;
	      nr/=5;
		 }
		 if (d5==p) {n=i;break;}
		 
	}
	
	fout<<n<<"\n";
	}
	fout.close();
	fin.close();
	return 0;
}