The digits of a calculator (with the exception of 0) are shown in the form indicated by the figure below, where there is also a button ``+":
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Two players A and B play in the following manner: A turns on the calculator and presses a digit, and then presses the button ``+". A passes the calculator to B, which presses a digit in the same row or column with the one pressed by A that is not the same as the last one pressed by A; and then presses + and returns the calculator to A, repeating the operation in this manner successively. The first player that reaches or exceeds the sum of 31 loses the game. Which of the two players have a winning strategy and what is it? algorithmcombinatorics proposedcombinatorics