Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Week | Date | Opponent | Score | Result | Record |
| --- | --- | --- | --- | --- | --- |
| 1 | July 9 | vs. Saskatchewan Roughriders | 31–21 | Win | 1–0 |
| 2 | July 16 | at Montreal Concordes | 36–0 | Win | 2–0 |
| 3 | July 24 | vs. Hamilton Tiger-Cats | 36–25 | Loss | 2–1 |
| 4 | Aug 1 | at Edmonton Eskimos | 32–26 | Win | 3–1 |
| 5 | Aug 8 | vs. BC Lions | 29–16 | Win | 4–1 |
| 6 | Aug 20 | at Calgary Stampeders | 35–4 | Win | 5–1 |
| 7 | Aug 28 | vs. Ottawa Rough Riders | 27–20 | Win | 6–1 |
| 8 | Sept 5 | at Saskatchewan Roughriders | 36–35 | Win | 7–1 |
| 9 | Sept 11 | vs. Calgary Stampeders | 15–11 | Loss | 7–2 |
| 10 | Sept 18 | at Ottawa Rough Riders | 38–28 | Loss | 7–3 |
| 11 | Sept 25 | vs. Montreal Concordes | 19–16 | Win | 8–3 |
| 12 | Oct 2 | at BC Lions | 29–19 | Win | 9–3 |
| 13 | Oct 11 | vs. Toronto Argonauts | 39–35 | Win | 10–3 |
| 14 | Oct 17 | at Toronto Argonauts | 29–16 | Win | 11–3 |
| 15 | Oct 23 | vs. Edmonton Eskimos | 33–17 | Loss | 11–4 |
| 16 | Nov 7 | at Hamilton Tiger-Cats | 24–21 | Loss | 11–5 |
Question:
how many teams played them in october?
Answer:
4