#include <fstream>

using namespace std;
ifstream fin("fact.in");
ofstream fout("fact.out");
long long p, n, k, x;
int main()
{
    fin>>p;
    if (p==0) n=1;
    else{
    k=1;n=5;
    while (k<p)
    {  n=n+5;
        x=n;
        while(x%5==0)
        {k++;
        x=x/5;
        //if (k==p) break;}
    }
    }}
    if (k==p)
    fout<<n;
    else fout<<-1;
    return 0;
}