The positive integer number \textbf{N} is given. We subtract from this number the sum of its digits. From the received number we soon subtract the sum of its digits and so on. This operation continues until the number is positive. How many times this operation will be repeated? \InputFile The number \textbf{N}, \textbf{0} < \textbf{N} ≤ \textbf{2147483647}. \OutputFile The number of performed operations.