# include <stdio.h>
long int p,i,n,k,ok,q;
int main ()
{
freopen ("fact.in","r",stdin);
freopen ("fact.out","w",stdout);
scanf ("%li",&p);
if (p>=1)
{
i=5;
while (ok==0)
{
q=5;
while (q<=i)
{
if (i%q==0)
k++;
q=q*5;
}
if (k==p)
ok=1;
i=i+5;
}
}
if (p==0)
printf ("1");
else
if (ok==1)
printf ("%li",i-5);
else
printf ("-1");
return 0;
}