#include<stdio.h>
long int p,k;
int n,x;
int main()
{freopen("fact.in","r",stdin);
 freopen("fact.out","w",stdout);
 scanf("%ld",&p);
 if(p==0)
  printf("%d",1);
 else
  {n=5;
   k=0;
   while(k<p)
    {x=n;
     if(x/5%5==0)
      while(x%5==0)
       {
	k++;
	x/=5;
       }
     else
      k++;
     n+=5;
    }
   if(k!=p)
    printf("%d",-1);
   else
    printf("%ld\n",n-5);
  }
return 0;
}