You will be given a definition of a task first, then some input of the task.
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.

Passage: The siege began on 19 November, when Ieyasu led 3,000 men across the Kizu River, destroying the fort there. A week later, he attacked the village of Imafuku with 1,500 men, against a defending force of 600. With the aid of a squad wielding arquebuses, the shogunate forces claimed another victory. Several more small forts and villages were attacked before the siege of Osaka Castle itself began on 4 December. The Sanada-maru was an earthwork barbican defended by Sanada Yukimura and 7,000 men, on behalf of the Toyotomi. The Shogun's armies were repeatedly repelled, and Sanada and his men launched a number of attacks against the siege lines, breaking through thrice. Ieyasu then resorted to artillery as well as men to dig under the walls. On 22 January the Winter Siege was ended, with Toyotomi Hideyori pledging to not rise in rebellion. He also allowed Ieyasu to tear down the walls of the outer layer of defenses, and fill in the outer moat of Osaka Castle.
Question: How many more men did Ieyasu have than the defending force?
Answer type: Number
Output:
900.