#include<fstream.h>
int n,p;

int main()
{
    ifstream in("fact.in"); 
    in>>p;
    n=125*(p/31);
    p=p-31*(p/31);
    int m;
    while(p>0)
        {
            n+=5;
            m=n;
            while(m%5==0)
                {
                    m=m/5;
                    p--;
                }
        }
    
    ofstream out("fact.out");
    if (p==0)
        out<<n;
    if (p<0)
        out<<-1;
    
    return 0;
}