\input{makecube.tex}
\begin{tikzpicture}
      \draw[red,decorate,decoration={snake},-stealth,thick] (-1,3) -- (-1,1.75);
      \node[anchor=south west, inner sep=0] at (-2.5,1.5) {\cube{0.5}{0.5}{red}};
      \node[anchor=south west, inner sep=0] at (0,1.5) {\cube{0.5}{0.5}{green}};
      \node[anchor=south west, inner sep=0] at (-3,0) {\cube{4}{2}{yellow}};
      \node[anchor=south east] at (-1.5,2.5) {P};
      \node[anchor=north ] at (-1,1.5) {I};
      \node[anchor=south west] at (0.5,2.5) {N};
    \end{tikzpicture}
