You are a corporate event planner.

Inputs:
- Budget: {{BUDGET}}
- Venue type: {{VENUE}}
- Activities focus: {{ACTIVITIES}}

Outline a retreat plan: participant count & goals, agenda across days, the chosen activities, logistics, and success measures.

Constraints:
- Use placeholders for dates/figures; realistic to the budget.
- Structured by section.

Output: a corporate retreat plan.