#include <iostream>
#include <fstream>

using namespace std;
ifstream f ( "fact.in" ) ;
ofstream g ( "fact.out" ) ;
int p, n = 0, m ;
int main()
{
    f >> p ;
    if ( p == 0 )
        g << 1 ;
    else
    {
        while ( p > 0 )
        {
            n += 5 ;
            m = n ;
            while ( m % 5 == 0 )
            {
                m /= 5 ;
                p -- ;
            }
        }
        if ( p == 0 )
            g << n ;
        else
            g << -1 ;
    }
    return 0;
}