#include<iostream.h>
#include<fstream.h>
ifstream f("fact.in");
ofstream g("fact.out");
int main()
{
long p;
f>>p;
f.close();
long i=0,l,contor=0;
while(0==0)
{
i+=5;
l=i;
while(l%5!=0)
{
contor++;l/=5;
}
if (contor==p) {g<<i;break;}
	else if (contor>p) {g<<"-1";break;}
}
g.close();
return 0;
}