MathDB
2013 ToT Spring Junior O p2, x9, delete digit 1, obtain A+1 from A?

Source:

March 4, 2020
combinatoricsDigitnumber theory

Problem Statement

There is a positive integer AA. Two operations are allowed: increasing this number by 99 and deleting a digit equal to 11 from any position. Is it always possible to obtain A+1A+1 by applying these operations several times?
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