#include <fstream> 
using namespace std; 
int main() 
{ 
    long long  p,g,i,cif,X;
    ifstream cin("fact.in"); 
    ofstream cout("fact.out"); 
    cin>>p; 
   
   for(i=5;cif<p;i+=5) 
   { 
       X=i; 
       while (X%5==0) 
       X/=5;
       cif++; 
} 
  if (p==0) 
  g<<1; 
  else
  cif==p?g<<i-5:g<<-1; 
   
   cin.close(); 
   cout.close(); 
   return 0; 
}