program tije;
    var i,j,n,k:longint;    f,g:text;  
    begin  
    assign(f,'tije.in'); reset(f);  
    assign(g,'tije.out'); rewrite(g);  
    read(f,n);  
    for i:=n-1 downto 1 do
          begin  
          for j:=n downto 1 do
                  begin  
                  for k:=1 to i shr 3 do writeln(g,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1,#13,j,' ',j+1);  
                  for k:=1 to i and 7 do writeln(g,j,' ',j+1);  
                  end;  
         for k:=1 to i shr 3 do writeln(g,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1,#13,n+1,' ',1);  
         for k:=1 to i and 7 do writeln(g,n+1,' ',1);  
         end;  
    close(f); close(g);  
   end.