#include <fstream>

using namespace std;
ifstream cin("fact.in");
ofstream cout("fact.out");

int main()
{
    int p,n=0;
    cin>>p;
    if(p==0)
    {
        cout<<1;
        return 0;
    }
    while(p>0)
    {
        n+=5;
        int nt=n;
        while(nt%5==0)
        {
            nt/=5;
            p--;
        }

    }
    if(p==0)
        cout<<n;
    else cout<<-1;
    return 0;
}