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:
| Driver | Constructor | Laps | Time/Retired | Grid |
| --- | --- | --- | --- | --- |
| Jackie Stewart | Tyrrell - Ford | 72.0 | 1:39:12.45 | 2.0 |
| François Cevert | Tyrrell - Ford | 72.0 | + 15.83 | 3.0 |
| James Hunt | March - Ford | 72.0 | + 1:03.01 | 7.0 |
| Peter Revson | McLaren - Ford | 72.0 | + 1:09.13 | 6.0 |
| Jean-Pierre Beltoise | BRM | 72.0 | + 1:13.37 | 9.0 |
| Gijs Van Lennep | Iso Marlboro - Ford | 70.0 | + 2 Laps | 20.0 |
| Carlos Pace | Surtees - Ford | 69.0 | + 3 Laps | 8.0 |
| Clay Regazzoni | BRM | 68.0 | + 4 Laps | 12.0 |
| Howden Ganley | Iso Marlboro - Ford | 68.0 | + 4 Laps | 15.0 |
| George Follmer | Shadow - Ford | 67.0 | + 5 Laps | 22.0 |
| Ronnie Peterson | Lotus - Ford | 66.0 | Engine | 1.0 |
| Graham Hill | Shadow - Ford | 56.0 | Not Classified | 17.0 |
| Niki Lauda | BRM | 52.0 | Fuel Pump | 11.0 |
| Mike Hailwood | Surtees - Ford | 52.0 | Electrical | 24.0 |
| Denny Hulme | McLaren - Ford | 31.0 | Engine | 4.0 |
| Wilson Fittipaldi | Brabham - Ford | 27.0 | Accident | 13.0 |
| Chris Amon | Tecno | 22.0 | Fuel System | 19.0 |
| Carlos Reutemann | Brabham - Ford | 9.0 | Tyre | 5.0 |
| David Purley | March - Ford | 8.0 | Withdrew | 21.0 |
| Roger Williamson | March - Ford | 7.0 | Fatal Accident | 18.0 |
| Emerson Fittipaldi | Lotus - Ford | 2.0 | Physical | 16.0 |
| Mike Beuttler | March - Ford | 2.0 | Electrical | 23.0 |
| Jackie Oliver | Shadow - Ford | 1.0 | Accident | 10.0 |
| Rikky von Opel | Ensign - Ford | 0.0 | Non Starter | 14.0 |
Question:
What is the top grid that laps less than 66 and a retried engine?
Answer:
4.0