Given the following passage  "After the financial crisis of 2007–08, it was known in 2008–2009 that two Portuguese banks (Banco Português de Negócios (BPN) and Banco Privado Português (BPP)) had been accumulating losses for years due to bad investments, embezzlement and accounting fraud. The case of BPN was particularly serious because of its size, market share, and the political implications - Portugal's then current President, Cavaco Silva, and some of his political allies, maintained personal and business relationships with the bank and its CEO, who was eventually charged and arrested for fraud and other crimes. In the grounds of avoiding a potentially serious financial crisis in the Portuguese economy, the Portuguese government decided to give them a bailout, eventually at a future loss to taxpayers and to the Portuguese people in general.",  answer the following question. Note that the answer is present within the text.  Question: Silva had a relationship with which bank?
BPN