Hi want to assign the correct class and year to my data. From what it looks like on the right to the left. how do I go about this for a large file
| year | class | student | | | year | class | student |
| 1 | a | 1 | | | 1 | a | 1 |
| | | 2 | | | 1 | a | 2 |
| 1 | b | 1 | | | 1 | b | 1 |
| | | 2 | | | 1 | b | 2 |
| | | 3 | | | 1 | b | 3 |
| 2 | a | 1 | | | 2 | a | 1 |
| | | 2 | | | 2 | a | 2 |
