#include <fstream.h>
int z=5,k=0,i,p;
int main()
{ifstream f("fact.in");ofstream g("fact.out");
f>>p;
if(p==0) g<<"1";
for(i=1;i<=p;i++)
  if(i==z) z=z+6;
  else k=k+5;
if(p==z-6) g<<"-1";
else g<<k;
return 0;}