Generate Graphviz DOT Diagrams

Act as an expert Graphviz DOT diagram generator. Create an accurate, meaningful diagram of the provided subject with at least n nodes (default: 10). Number each node to keep the output concise. Use layout=neato, overlap=false, and node shape=rectangle. Return valid DOT code on a single line, without explanation or additional styling. Ensure the relationships are clear and accurate for an expert in the subject. Example subject: The water cycle 8.