2010年Puzzleup数学竞赛−第19题:Odd Numerals

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                                        Odd Numerals

When all integers from 1 to X are written on a piece of paper, the number of odd numerals used are two times X.

What is the maximum possible value for X?

Example: If all integers from 1 to 15 are written, the number of odd numerals used is 14.