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:
| Name | Country | Status | Transfer window | Transfer fee |
| --- | --- | --- | --- | --- |
| Roberto Carlos | BRA | Contract Ended | Summer | Free |
| Helguera | ESP | Contract Ended | Summer | Free |
| Pavón | ESP | Contract Ended | Summer | Free |
| Beckham | ENG | Contract Ended | Summer | Free |
| Mejía | ESP | Contract Ended | Summer | Free |
| Miñambres | ESP | Retired | Summer | Free |
| Cicinho | BRA | Transferred | Summer | € 9M |
| Woodgate | ENG | Transferred | Summer | £ 7M |
| López | ESP | Transferred | Summer | € 7M |
| Émerson | BRA | Transferred | Summer | € 5M |
| Diogo | URY | Transferred | Summer | € 4.5M |
| De la Red | ESP | Transferred | Summer | loan |
| Bravo | ESP | Transferred | Summer | € 2.3M |
| Javi García | ESP | Transferred | Summer | Undisclosed |
| Rayco | ESP | Transferred | Summer | Undisclosed |
| Miguel Palencia | ESP | Transferred | Summer | Undisclosed |
| Reyes | ESP | Loan Ended | Summer | — |
| Cassano | ITA | Loaned Out | Summer | — |
| García | URY | Loaned Out | Summer | — |
| González | ESP | Loaned Out | Summer | — |
| Agus | ESP | Loaned Out | Summer | — |
| Granero | ESP | Loaned Out | Summer | — |
| González | ESP | Loaned Out | Winter | — |
Question:
What is the transfer fee of Diogo?
Answer:
€ 4.5M