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:
| Frequency | Callsign | Brand | City of License | Type |
| --- | --- | --- | --- | --- |
| 580.0 | XEHP | La Mas Prendida | Ciudad Victoria | Norteño |
| 640.0 | XETAM | La Poderosa | Santa Elena | Norteño |
| 970.0 | XEBJ-AM | Radio 970 | Ciudad Victoria | Contemporary |
| 1340.0 | XERPV-AM | La Cotorra | Ciudad Victoria | Norteño |
| 1380.0 | XEGW | Planeta W 1380 | Ciudad Victoria | Christian Pop |
| 1480.0 | XEVIC | Radio Tamaulipas | Ciudad Victoria | State Government |
Question:
What is Brand, when Frequency is "640"?
Answer:
La Poderosa