Detailed Instructions: This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.
Q: Passage: On April 17, 13 ships arrived at Tokunoshima and dispersed. Two ships arrived at Kanaguma, but nothing happened. Eight ships arrived at Wanya. The ships were besieged all night by 1,000 people. On April 18, Satsuma troops disembarked, fired into the crowds, and killed 50 people. Three ships arrived at Akitoku, and were attacked at the water's edge by the Akitoku people. However, troops quickly fought back and killed 20-30 people. The Satsuma fleet also arrived at Akitoku at 4pm, April 20. On April 21, Kabayama left for Okierabu Island with 10 ships in advance. Others left Tokunoshima at 10am, April 24, and arrived at Okierabu at sunset. They met Kabayama and his ships there, and quickly departed for Ryukyu Island.
Question: How many total ships arrived at Tokunoshima, Kanaguma, and Wanya on April 17?
Answer type: Number
A:
23.