#include<iostream>
#include<stdio.h>
FILE *f,*g;
int main ()
{
int p,n=0,n1=0,nr=0,t=1;
f=fopen("fact.in","r");
g=fopen("fact.out","w");
fscanf(f,"%d",p);
if(!p) fprintf(g,"1");
else
{
while(nr<p)
{
 n+=5; n1=n;
 while(!(n1%5)&&t)
 {
  nr++;
  n1=n1/5;
  if(nr>p) t=0;}
}
if(p==nr) fprintf(g,"%d",n);
else fprintf(g,"-1");
}fclose(f); fclose(g);
return 0;
}