#include <fstream.h>

ifstream fin("fact.in");
ofstream fout("fact.out");

long P,N,put;


void factorial()
{
long z;put=1;
if (P==0) N=1;
    else if (P==1) N=5;
	else { 		 N=5;
			if(P>=100000)  { N=400005;put=100000;}


			while (put<P)
			{N=N+5;z=N;
			    while (z%5==0)
				{z=z/5;
				 put=put+1;
				  }
			  }
	     }
}

int main()
{fin>>P;
factorial();
if (put>P&&P>3) N=-1;


fout<<N;
fin.close();
fout.close();
return 0;
}