#include <iostream>
#include <fstream>

using namespace std;

ifstream f("fact.in");
ofstream g("fact.out");

int i,x,p,c,a;

int main()
{
    f>>p;
    if(p==0)
        g<<1;
    else
    for(i=1; i<10000000000; ++i)
    {
        x=i;
        c=a+1;
        while(x-x/5*5==0)
        {
            x/=5;
            ++c;
        }
        if(p<c)
        {
            g<<-1;
            break;
        }
        else
        if(p==c)
        {
            g<<i*5;
            break;
        }
        a=c;
    }
}