program fractii;

        var fi,fo: text;
            x,y: integer;
            k,k1: byte;
            i,n,j,m:integer;
begin
     assign(fi,'fractii.in'); reset(fi);
     assign(fo,'fractii.out'); rewrite(fo);
     readln(fi,n);

     for i:=1 to n do
                   for j:=1 to n do begin
                                    k:=1;
                                    while (k<n) and (i mod k<>0) and  (j mod k<>0) do inc(k);
                                    if k=1 then
                                                 if k=i then begin
                                                                          write(fo,i,'/',j,' ');
                                                                          inc(k1);
                                                                          end
                                                         else begin
                                                              k:=2;m:=k;
                                                              while (k<n) and ((i mod k<>0) or (j mod k<>0)) do inc(k);
                                                              if (k=n) then if not((i=j)and(j=n)) then begin     write(fo,i,'/',j,' ');
                                                                                               inc(k1);
                                                                                               end;


                                                              end;
                                    end;
            writeln(fo,k1);
close(fo);
end.