# include <fstream>
using namespace std;
int main ()
{
    long long int p, i, nrz=0, c, n, x[100], y[100], s;
    ifstream fin ("fact.in");
    ofstream fout ("fact.out");
    x[1]=1, y[1]=5;
    for (i=2;i<=14;i++)
        x[i]=x[i-1]*5+1, y[i]=y[i-1]*5;
    fin>>p;
    if (p==0)
       fout<<"1";
    else
    {
       for (i=1;i<12 && nrz==0;i++)
           if (p>x[i] && p<x[i+1])
              s=y[i], nrz=x[i]; 
       for (i=s+5;nrz<p;i+=5)
       {
           c=i, n=i;
           while (c%5==0)
           {
                 nrz++;
                 c/=5;
           }
       }
       if (nrz==p)
          fout<<n;
       else
          fout<<"-1";
    }
    return 0; 
}