#include <iostream>
#include <fstream>
using namespace std;
long z,y,j,i,p,nr;
int main()
{
    ifstream f("fact.in");
    ofstream g("fact.out");
    f>>p;
    if (p==0) {g<<1;return 0;}
    else
    {
        y=(p*4+p*5)/2;
        for (i=1;i<=y;i++)
        {
            z=i;
            while (z%5==0)
            {
                nr++;
                z=z/5;
            }
        }
        if (nr==p) {g<<y;return 0;}
        else if (nr<p) for (i=y;i<=p*5;i+5)
                       {

                            nr=0;
                            z=i;
                            while (z%5==0)
                            {
                                nr++;
                                z=z/5;
                            }
                            if (nr==p) {g<<i;return 0;}
                       }
        else if (nr>p) for (i=p*4;i<=y;i+5)
                       {
                            nr=0;
                            z=i;
                            while (z%5==0)
                            {
                                nr++;
                                z=z/5;
                            }
                            if (nr==p) {g<<i;return 0;}
                       }
    }
    g<<-1;
    return 0;
}