# Large square number

Find the largest possible 3-digit positive integer $$N$$ such that $$N^2$$ is of the form $$ABC, ABD$$, where $$A$$, $$B$$, $$C$$, and $$D$$ are (not necessarily distinct) digits and $$D = C+1$$.

(An example of a number of this form is 123,124 or 998,999.)

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