#include <iostream>
#include <fstream>

using namespace std;

ifstream in("fact.in");
ofstream out("fact.out");

int nrz(int n){
    int cont=0;
    while(n%10==0){
        n=n/10;
        cont=cont+1;
    }
    return cont;
}
int main()
{
   /*int st,n, p, c, nr;
   st=0;
   long long int dr=10000000000000000000;
   n=1;
   in >> p;
   while(n){
    c=(st+dr)/2;
    nr=nrz(c);
    if(nr==p && st==dr){
        n=st;
        break;
    }
    if(dr<st){
        n=-1;
        break;
    }
    if(p>nr){
        st=c+1;
    }
    else{
        dr=c-1;
    }
   }
   out << n;
}*/
    int i,p,c,j;
    in >> p;
    i=5;
    c=1;
    if(p==0){
        out << 1;
    }
    else{
       while(c!=p)
    {
        i=i+5;
        j=i;
        while(j%5==0){
            c=c+1;
            j=j/5;

        }
        if(c>p){
            i=-1;
            break;
        }
    }

    out << i;
    }
    }