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 | Name | Nationality | Time | Notes |
| --- | --- | --- | --- | --- |
|  | Jill Sterkel | United States | 1:00.53 | NR, GR |
|  | Lisa Buese | United States | 1:00.59 |  |
|  | Nancy Garapick | Canada | 1:02.96 |  |
| 4 | Shelley Cramer | U.S. Virgin Islands | 1:03.51 | NR |
| 5 | Susan Sloan | Canada | 1:03.52 |  |
| 6 | Maria Paris | Costa Rica | 1:03.58 |  |
| 7 | Rosanna Juncos | Argentina | 1:04.75 |  |
| 8 | Adriana Pereira | Brazil | 1:06.79 |  |
Question:
which two countries has the most number of participants?
Answer:
United States, Canada