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MathNet 2019-part-04 — 184 problems (EN–VI) Question 90

Math Olympiad Vault · MathNet 2019-part-04 — 184 problems (EN–VI)

Question 90

Starting with a positive integer, a *fragment* of that number is any positive number obtained by removing one or more digits from the beginning and/or end of that number. For example: the numbers $2$, $1$, $9$, $20$, $19$, and $201$ are the fragments of $2019$.
What is the smallest positive integer $n$ such that the following holds: there is a fragment of $n$ such that when you add this fragment to $n$ itself, you get $2019$?