Update usaco-923.mdx

Author: SansPapyrus683

solutions/silver/usaco-923.mdx

@@ -2,40 +2,37 @@
 id: usaco-923
 source: USACO Gold 2019 February
 title: Painting the Barn
-authors: Kevin Sheng, KJ Karaisz
+author: Kevin Sheng, KJ Karaisz
 ---
 
 **Note:** This editorial assumes one already has a firm grasp of the
 [silver](http://www.usaco.org/current/data/sol_paintbarn_silver_feb19.html)
 version of this problem.
 
 <Spoiler title="Hint 1">
-Think about one rectangle for now.
 
-    <Spoiler title="Hint 1.1">
-    What cells can you ignore?
-    </Spoiler>
-
-    <Spoiler title="Hint 1.2">
-    What if the problem was one-dimensional?
-    </Spoiler>
+Say FJ could only paint one rectangle of paint over the barn.
+Then, this problem would turn into finding the
+[maximum sum of a submatrix](https://stackoverflow.com/a/18220549/12128483).
 
 </Spoiler>
 
 <Spoiler title="Hint 2">
+
 So you have your one rectangle now. How do you make this algorithm work for two?
 
-    <Spoiler title="Hint 2.1">
-    You could certainly run the algorithm on another rectangle.
-    </Spoiler>
+Try to think about how you can guarantee disjoint rectangles!
+
+</Spoiler>
+
+<Spoiler title="Answer to Hint 2">
 
-    <Spoiler title="Hint 2.2">
-    *Multiple* rectangles, perhaps?
-    </Spoiler>
+If two rectangles are disjoint, there can always be a horizontal or vertical line separating them.
 
 </Spoiler>
 
 <Spoiler title="Solution">
+
 [Official Analysis (C++)](http://www.usaco.org/current/data/sol_paintbarn_gold_feb19.html)
 
 ## Explanation