\begin{tikzpicture}[scale=1, transform shape,circuit logic IEC]   
\tikzstyle{branch}=[fill,shape=circle,minimum size=1pt,inner sep=pt]

\node[not gate] at (1,1)(nota){};
\node[not gate] at (1,3)(notb){};
\node[nand gate] at (3,2)(n2){};

\node (a) at (0,1) {$a$};
\node (b) at (0,3) {$b$};
\node (out1) at (2.,2) {};
\node (y) at (4.25,2) {$out$};


\draw(nota.input) -- (a);
\draw(notb.input) -- (b);
\draw(nota.output) --++ (0.5,0) --++ (0,0.825)-| ($(n2.input 2)$);
\draw(notb.output) --++ (0.5,0) --++ (0,-0.825)-| ($(n2.input 1)$);
%\draw(n2.input 2) -| ($(out1)$);

\draw(n2.output) -- (y);

\end{tikzpicture}