#define DEBUG 0
#define GENERATOR 0

#if GENERATOR == 0
#include<fstream>
using namespace std;

/*************************************************************************
 *         	0	1	2	3	4	5       6        *
 *      0	0	6	12	18	24	30               *
 *      1	31	37	43	49	55	61               *
 *      2	62	68	74	80	86	92               *
 *      3	93	99	105	111	117	123              *
 *      4	124	130	136	142	148	154	155      *
 *************************************************************************/

inline int fact(int zeros)
{
    int mod = ((zeros+1)%156);
    // From 0 to 155 there are 31 non-numbers
    int non = ((zeros+1)/156)*31;

    // < 156, if (number+1 % 31) % 6 is zero, it is a non
    if ((mod % 31) % 6 == 0) return -1;
    if (mod == 155) return -1;

    // Add rows
    non += (mod / 31) * 6;

    // Add elements before
    non += (mod % 31) / 6;

    return (zeros - non) * 5;
}

int main()
{
    int p;
    ifstream in ("fact.in");
    ofstream out ("fact.out");
    in>>p;

#if DEBUG == 1
    for (p = 110; p < 200; p++) {
        out<<"("<<p<<") -> ";
#endif
        if (p == 0) out<<1;
        else out<<fact(p);
#if DEBUG == 1
        out<<endl;
    }
#endif
    out.close();
    return 0;
}

#endif

#if GENERATOR == 1
#include<iostream.h>
#include<fstream.h>

ofstream out("fact.out");

int main()
{
    for (int p = 0; p < 10000; p++) {
            int ok=0,n,twos=0,fives=0,pp;


            for(n=1;ok==0 && n>0;n++)
            {
                    pp=n;
                    while(pp%5==0 || pp%2==0){
                            if (pp%2==0) { twos++; pp=pp/2;}
                            if (pp%5==0) { fives++; pp=pp/5;}
                            }

                    if(twos>=p && fives>=p) ok=n;
            }

            out<<"("<<p<<")"<<" -> ";
            if(ok==0) out<<-1;
            else out<<ok;
            out<<endl;

            if (p%1000 == 0) cout<<"\rLoading..."<<p*100/10000<<"%";
    }
    
    out.close();


    return 0;
}
#endif