I tried several approaches, but none of them worked... Here is my tree code:
\begin{figure}[bh!]
\centering
\begin{tikzpicture}[ level distance=1cm, growth parent anchor=east, grow=right,scale=0.78,
level distance=1cm,
]
\tikzstyle{every node}=[font=\footnotesize, text width=5mm,anchor=east]
\Tree[.{0} [.{1} [.{1} [.{1} [.{1} [.{2} [.{7} [.{9} [.{4} [.{33} ] [.{474} ] ] [.{478} ] ] [.{487} ] ] [.{494} ] ] [.{496} ] ] [.{497} ] ] [.{498} ] ] [.{499} ] ] [.{4} [.{13} [.{4} [.{4} [.{7} [.{25} [.{9} [.{120} [.{314} ] [.{314} ] ] [.{434} ] ] [.{443} ] ] [.{468} ] ] [.{475} ] ] [.{479} ] ] [.{483} ] ] [.{496} ] ] [.{1} [.{2} [.{18} [.{39} [.{2} [.{55} [.{56} [.{327} ] [.{327} ] ] [.{383} ] ] [.{438} ] ] [.{440} ] ] [.{479} ] ] [.{497} ] ] [.{499} ] ] [.{3} [.{10} [.{2} [.{3} [.{6} [.{8} [.{7} [.{16} [.{32} ] [.{445} ] ] [.{461} ] ] [.{468} ] ] [.{476} ] ] [.{482} ] ] [.{485} ] ] [.{487} ] ] [.{497} ] ] [.{6} [.{9} [.{7} [.{1} [.{3} [.{3} [.{9} [.{14} [.{24} ] [.{448} ] ] [.{462} ] ] [.{471} ] ] [.{474} ] ] [.{477} ] ] [.{478} ] ] [.{485} ] ] [.{494} ] ] [.{444} [.{56} ] [.{56} ] ] ]
\end{tikzpicture}
\end{figure}
and here is how it looks like:

I want it to be narrower, i.e., pushing together the siblings at level one so there is no free space between the branches - or at least a bit less space...
