Compare the number of business between the category of "Men's Clothing" and "Women's Clothing".
category of "Men's Clothing" refers to category_name = 'Men''s Clothing'; "Women's Clothing" refers to category_name = 'Women''s Clothing'
SELECT SUM(CASE WHEN T1.category_name = 'Men''s Clothing' THEN 1 ELSE 0 END) - SUM(CASE WHEN T1.category_name = 'Women''s Clothing' THEN 1 ELSE 0 END) AS diff FROM Categories AS T1 INNER JOIN Business_Categories AS T2 ON T1.category_id = T2.category_id