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MathNet 2013 Question 18

Math Olympiad Vault · MathNet 2013

Question 18

The odd number of the asterisks are written on the blackboard: $\underbrace{**\dots*}_{2n+1}$.
Ann and Bob play the following game. They, in turn (Ann starts), replace one of the asterisks in the expression $\underbrace{**\dots*}_{2n+1}$ by any of the digits from $0$ to $9$ (the first left asterisk cannot be replaced by $0$). Ann wins if the obtained number is divisible by $11$, otherwise Bob wins.
Who of the players wins if both of them play to win?