The difference between the squares of two consecutive odd integers is a…

The difference between the squares of two consecutive odd integers is a square<1000 whose root equals the combined sum of the digits of the two integers. What is the sum of the digits M of the larger integer?

Its source gives only the correct option, without the working.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #90867