Program infoarenafact;
   var p,n:longint;
       fin,fou:text;
begin

 assign(fin,'fact.in');
 reset(fin);
 readln(fin,p);
 close(fin);
 if p=0 then n:=1
 else
 if p<=4 then
  begin
    n:=p*5;
  end
 else if p=5 then n:=-1
      else if p>5 then n:=(p*5)-5;
 assign(fou,'fact.out');
 rewrite(fou);
 write(fou,n);
 close(fou);
 readln;
end.