program PbFractii;
var f,g:text; n,i,j,nr:integer; ok:boolean;
begin
assign(f,'fractii.in');reset(f);
assign(g,'fractii.out');rewrite(g);
read(f,n);
for i:=1 to n do

 for j:=1 to n do
  begin
  if (i=1) or (j=1) then begin write(i,'/',j,' '); nr:=nr+1;end;
  ok:=true;
   if i mod j=0 then ok:=false else if j mod i=0 then ok:=false;

  if ok=true then begin  nr:=nr+1; write(i,'/',j,' ');end;
 end;
write(g,nr);
close(f);close(g);
end.