Commutative diagram with non-uniform arrows

Question

I wrote following program for a commutative diagram.

\begin{tikzcd}
0\arrow[r] & M\arrow[r]\arrow[d] & N\arrow[r]\arrow[d] & K\arrow[d]\\
0\arrow[r] & M'\arrow[r]         & N' \arrow[r]        & K' \\
\end{tikzcd}

The output is the following.

Q. If I do not want the $0$ and arrow going at M, and want to put an arrow with end 0 after K, what should be change in commands? I added/removed some natural commands from above program; but it was always creating error. For example, I removed 0\arrow[r] from first command-line in above commands; but it produced error.

Answer 1

I would do this as follows:

\documentclass{article}

\usepackage{tikz-cd}

\begin{document}

\begin{tikzcd}
  & M\arrow[r]\arrow[d] & N\arrow[r]\arrow[d] & K\arrow[d]\arrow[r] & 0\\
  0\arrow[r] & M'\arrow[r] & N' \arrow[r] & K' \\
\end{tikzcd}

\end{document}