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:
| Case/Suffix | we two | you and I | you two | them two (the two) | who-two |
| --- | --- | --- | --- | --- | --- |
| nom-acc-inst | ngalbe | ngœba | ngipel | palai (Boigu pale) | ngawal |
| gen. | ngalben | ngœban | ngipen | palamun (Boigu palemun) | (as for singular) |
| dat. | ngalbelpa | ngœbalpa | ngipelpa | palamulpa (Boigu palemulpa) | (as for singular) |
| abl. | ngalbelngu | ngœbalngu | ngipelngu | palamulngu (Boigu palemulngu) | (as for singular) |
| loc. | ngalbeniya | ngœbaniya | ngipeniya | palamuniya (Boigu palemuniya) | (as for singular) |
Question:
What is who-two when you two is ngipelngu?
Answer:
(as for singular)