You are playing the Regex Pattern Matcher game against o3-mini - (low).

Game history:
Turn 1: o3-mini - (low) proposed text with target items: ["complex.email+filter@example.co.uk","+44 20 7946 0958","2021/12/31","temp007"]
claude 3.7 sonnet (high2) provided pattern: complex\.email\+filter@example\.co\.uk|\+44 20 7946 0958|2021\/12\/31|\btemp007\b (SUCCESS)

Current turn: 2 of 10
You are the PROPOSER.

Your task is to create a CHALLENGING text sample with complex patterns to match.
Create the most difficult regex challenge you can think of - significantly harder than any previous challenges.

Guidelines for creating a DIFFICULT challenge:
1. Use complex patterns that require advanced regex techniques to match.
2. Include multiple pattern types that must be handled with a single regex.
3. Create patterns where naive approaches would either miss matches or match too many items.
4. ADVANCED PATTERNS to consider:
   - Mixed formats (emails, phone numbers, dates with different separators)
... (truncated)