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:
| Team | Tries for | Tries against | Try diff | Points for | Points against | Points diff |
| --- | --- | --- | --- | --- | --- | --- |
| Bourgoin | 27 | 4 | +23 | 196 | 66 | +130 |
| Bordeaux-Bègles | 29 | 13 | +16 | 195 | 99 | +96 |
| Swansea | 28 | 19 | +9 | 207 | 138 | +69 |
| Gloucester | 17 | 17 | 0 | 119 | 123 | −4 |
| Ebbw Vale | 6 | 36 | −30 | 48 | 243 | −195 |
| London Irish | 12 | 30 | −18 | 90 | 186 | −96 |
| Source : www.ercrugby.com | Source : www.ercrugby.com | Source : www.ercrugby.com | Source : www.ercrugby.com | Source : www.ercrugby.com | Source : www.ercrugby.com | Source : www.ercrugby.com |
Question:
What is points diff when points against is 123?
Answer:
−4