#include <iostream>
#include <fstream>
using namespace std;
long p,k,nr,h,i,hh,OK;
int main()
{
    ifstream fin("fact.in");
    ofstream fout("fact.out");
    fin>>p;
    k=0;
    nr=0;
    h=0;
    i=156;
    if(p==0)fout<<"1";
    else
    {
        while(nr+i<=p)
    {
        nr+=i;
        h+=625;
        k++;
        hh=h;
        while(hh%5==0)
        {
            nr++;
            hh/=5;
        }
        nr-=4;
    }
    if(nr==p)fout<<h;
    else
    {
        while(nr<p)
    {
        h+=5;
        hh=h;
        while(hh%5==0)
        {
            nr++;
            hh/=5;
        }
    }
    if(p==nr) fout<<h;
    else fout<<"-1";
    }
    }
    fin.close();
    fout.close();
}