var f,g:text;
    n,i,j,l:byte;
    k:longint;
    a:array[1..2,1..1000000] of byte;
begin
     assign(f,'tije.in'); reset(f);
     readln(f,n);
     close(f);
     assign(g,'tije.out');rewrite(g);
     k:=0;
     for i:=n-1 downto 1 do
     begin
          for j:=1 to i do
          begin
              k:=k+1;
              a[1,k]:=1;a[2,k]:=n+1;
          end;
          for l:=1 to n do
              for j:=1 to i do
                begin
                     k:=k+1;
                     a[1,k]:=l+1;a[2,k]:=l;
                end;
     end;
     if n=1 then begin
        writeln(g,'1',' ','2');
        writeln(g,'2',' ','1');
      end
      else begin
                for i:=1 to k do
                    writeln(g,a[i,1],' ',a[i,2]);
      end;
     close(g);
end.