GPT-5.3 Codex

Use 4 groups with one coordinator per group. 00:00–00:10: welcome and explain the activity. 00:10–00:20: distribute 21 collection bags to each group. 00:20–01:05: run the main activity. 01:05–01:20: collect feedback and reusable equipment. 01:20–01:30: clean the south bridge and check the inventory.

Count the 84 collection bags before visitors arrive. Confirm a clear entrance and an accessible work area at the south bridge, then give each of the 4 group leads the same timing sheet.

Supplies: 84 × $4.35 = $365.40. Reserve: $365.40 × 0.10 = $36.54. Planned total: $401.94. This is a planning calculation using the supplied prices.

Remove 21 units, leaving 63. Supplies become $274.05; a 10% reserve adds $27.40, for a total of $301.45.

Join River Cleanup Team this Sunday at the south bridge. Meet neighbors, learn together, and take part at your own pace. We will share the available collection bags across small groups. Supplies are limited, so please check with the welcome desk when you arrive.

River Cleanup Team Sunday · south bridge Welcome! Ask the desk about available collection bags and today’s small-group activities.

```python import csv def read_inventory(path): rows = [] with open(path, newline="", encoding="utf-8") as handle: reader = csv.DictReader(handle) if reader.fieldnames != ["item", "quantity"]: raise ValueError("Expected item,quantity columns") for line, row in enumerate(reader, 2): name = row["item"].strip() quantity = row["quantity"].strip() if not name or not quantity.isascii() or not quantity.isdecimal(): raise ValueError(f"Invalid inventory row {line}") rows.append((name, int(quantity))) return rows # Example row: collection bags,84 ```

The row `collection bags,84` should pass. The row `collection bags,-1` should raise a ValueError because a negative quantity is outside the stated inventory contract. An empty item should also fail.

Handover — River Cleanup Team Location: south bridge; day: Sunday. Inventory: 84 collection bags, allocated as 4 groups × 21. Before opening: count supplies, set the welcome desk, and confirm group leads. During the event: record shortages and visitor questions. After closing: count returns and write one improvement for the next meeting.

Ask: “Were 21 collection bags per group enough for the activity, and which step created the longest wait?” Record the answer beside the returned inventory count.

You are welcome to check in at the desk when you arrive. A coordinator can explain the current activity and see whether a group has space and spare collection bags. If the activity is already full, we can help you observe or find the next joining point.

Avoid guaranteeing a place or a set of collection bags before checking the group capacity. Keep the reply specific to the south bridge session and offer a clear next step: speak with the welcome desk.