	\tikzstyle{input_neuron}=[circle,draw=red!50,fill=red!10,thick,minimum size=6mm]
	\tikzstyle{hidden_neuron}=[circle,draw=blue!50,fill=cyan!10,thick,minimum size=6mm]
	\tikzstyle{output_neuron}=[circle,draw=green!50,fill=green!10,thick,minimum size=6mm]
	\tikzstyle{cpy_neuron}=[circle,draw=red!50,fill=red!50,thick,minimum size=6mm]
	\tikzstyle{input}=[circle,draw=black!50,fill=black!20,thick,minimum size=6mm]
	
\begin{center}
%\resizebox{}{}{
\begin{tikzpicture}[scale=0.75]
    

	\node [hidden_neuron] (neuron1) at (10,7.5)  {A};
	\node [hidden_neuron] (neuron2) at (8,5.5)  {D};
	\node [hidden_neuron] (neuron3) at (10,3.5)  {C};
	\node [hidden_neuron] (neuron4) at (12,5.5)  {B};
     \draw[blue,thick,] (neuron1) -- (neuron2); %A->B
     \draw[blue,thick,] (neuron2) -- (neuron3); %B->C
     \draw[blue,thick,] (neuron3) -- (neuron4); %C->D
     \draw[blue,thick,] (neuron4) -- (neuron1); %D->A


\end{tikzpicture}
%}
\end{center}
