#include <iostream>
#include <fstream>
using namespace std;
int S,n,i,p,P,d,c;
int main()
{fstream f("fact.in",ios::in);
    f>>P;
    P=1;
    for(i=1;i<=n;i++)
       p=P*i;
       while(p=!0)
       c=c%10;
       p=p/10;
       while(c=0)
       d=d+1;
       if (d=P)
       cout<<i;
       else
       cout<<-1;
    return 0;
}