#include <iostream>
#include <fstream>



using namespace std;



ifstream be("fact.in");
ofstream ki("fact.out");

int main()
{ int p,n,i=1,a;
be>>p;
be.close();
if(p==0) ki<<1;
else {n=5;
while(i<p){
    n=n+5;
    a=n;
    while(a%25==0){ i++;
                    a=a/5;}
    i++;

}

if(i>p) ki<<-1;
else ki<<n;}
ki.close();

return 0;

}