Instructions: In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Input: Passage: In 2019, Alexandrova had more success in the WTA Tour. Seeded sixth, she reached the quarterfinals of the St. Petersburg Ladies' Trophy, followed by a semifinal entry at the Hungarian Ladies Open. She entered the 3rd Round of the Premier Mandatory BNP Paribas Open in Indian Wells, after beating World No. 13 Caroline Wozniacki in three sets. She performed not satisfying on clay tournaments, except at French Open, reaching the third round of a Grand Slam tournament for the first time. In the grass court season, Alexandrova made it into the quarterfinals of the Premier Eastbourne International tournament, losing there to Karolina Pliskova. She achieved her best run in a Premier 5 tournament at the Rogers Cup, reaching the 3rd Round as qualifier. She lost to Serena Williams. After reaching the 2nd Round of the US Open and following Daria Kasatkina's 1st Round loss, Alexandrova became Russia's number one female tennis player.
 Link Information: none Question: How many grand slam tournaments have been won by the player Alexandrova lost to in  the Rogers Cup?
Output:
Answer: none