#include <iostream>
#include <fstream>
using namespace std;
int p,k=0,i=1,n=0,sum=1,h=1;
int main()
{
   ifstream fin("fact.in");
   ofstream fout("fact.out");


   fin>>p;
   while(p!=0)
   {
       h=h*10;
       p--;
   }
        while(n<=100)
        {
          n++;
          for(i=1;i<=n;i++)
          {
            sum=sum*i;
          }
          if(sum%h==0)
          break;
        }
        if(n!=1000)
        fout<<-1;
        else
        fout<<n;
    return 0;
}