#include <fstream>

using namespace std;

ifstream in ("fact.in");
ofstream out ("fact.out");
int p , n=1, s , cn , man;
int factorial (int n)
{
    int i , nr =1;
    for(i=2;i<=n;i++)
        nr=nr*i;
    return nr;
}
int main()
{
    in>>p;
    while(!man)
    {
        s=0;cn=n;
    n=factorial(n);
    while(n)
    {
        if(n%10==0) s++;
        n/=10;
    }
    if(s==p) {out<<cn;man=1;}
    if(s>p) {out<<-1;man=1;}
    n=cn+1;
    }
}