Some Quote Next Line

Allowing an unimportant mistake to pass without comment is a wonderful social grace.

Ideological differences are no excuse for rudeness.

This is the first level of quoting.

This is a paragraph in a nested blockquote.

Back to the first level.

This is a header.

1. This is the first list item.
2. This is the second list item.

A code block:

return 1 < 2 ? shell_exec('echo $input | $markdown_script') : 0;