#include <fstream>

using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
int n,x,c,p;
int main()
{
    fin>>n;
    if(n==0)fout<<1;
    else{
    while(x<n)
    {
        p+=5;c=p;
        while(c%5==0){c/=5;x++;}
    }
    if(x>n)fout<<-1;
    else fout<<p;}
    fout<<'\n';
    fin.close();
    fout.close();
    return 0;
}