#include<fstream>  
using namespace std;  
int main()  
{  
    ifstream in("fact.in");  
    ofstream out("fact.out");  
    unsigned long p,cc=0,pp,n;  
    in>>p;  
    if(p!=0)   
    {  
        for(n=5;cc<=p;n+=5)  
        {  
            pp=n;  
            while(pp%5==0)        
            {  
                cc++;   
                pp/=5;  
            }if(cc==p) break;  
        }  
    if(cc==p)   
        out<<n<<"\n";  
    else   
        out<<"-1"<<"\n";  
    }  
    else   
        out<<"1"<<"/n";  
    out.close();  
     in.close();  
     return 0;  
}