225. Fruit Garden. The gardener decided to create a new fruit garden. He planted young trees in rows so that a square was formed. In doing so, he had 146 extra seedlings left. But to increase the square by adding an extra row, the gardener had to buy 31 more trees.

How many trees are there in the garden at the end of the work?
225. Initially, there were 7890 saplings, from which a square of \(88 \times 88\) was formed, and 146 trees were left over. By purchasing an additional 31 trees, the gardener was able to increase the square to \(89 \times 89\), and the number of trees in the garden became 7921.