#include <fstream>

using namespace std;

int p,i,S,y;
ifstream cin ("fact.in");
ofstream cout("fact.out");

int main()
{
    cin>>p;
    if (p==0)
    {
        cout<<1;
        return 0;
    }
    S=0;
    for (i=5;i<=100000000;i+=5)
    {
        y=i;
        while (y%5==0)
        {
            S++;
            y/=5;
        }
        if (S==p)
        {
            cout<<i;
            return 0;
        }
        else if (S>p)
        {
            cout<<-1;
            return 0;
        }
    }
    return 0;
}