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:
| Rank | Rowers | Country | Time | Notes |
| --- | --- | --- | --- | --- |
| 1.0 | Zac Purchase , Mark Hunter | Great Britain | 6:13.69 | SA/B |
| 2.0 | Dimitrios Mougios , Vasileios Polymeros | Greece | 6:16.10 | SA/B |
| 3.0 | Jonathan Koch , Manuel Brehmer | Germany | 6:21.99 | R |
| 4.0 | Kazushige Ura , Daisaku Takeda | Japan | 6:24.21 | R |
| 5.0 | Mohamed Ryad Garidi , Kamel Ait Daoud | Algeria | 6:43.94 | R |
Question:
What are the notes with the time 6:24.21?
Answer:
R