按照下面方法对整数x进行分类：如果x是一个个位数，则x属于x类；否则将x的各位上的数码累加，得到一个新的x，依次迭代，可以得到x的所属类。比如说24，2+4=6，则24的类别数是6；39，3+9=12，1+2=3，则39的类别数是3。输入 每行输入一个非负整数n，n的位数<500，n为0时结束。输出 每行输出对应整数的分类数。-In accordance with the following methods for integer x classification: if x is a number, then x belongs to the X class　otherwise it will x you the digital accumulation, and get a new x iteration, in turn, class of the X can be obtained. For example, 24, 2+4=6, the number of category 24 is 6　the 39, 3+9=12, 1+2=3, the number of category 39 is 3. Input the input of a non-negative integer N per line, the number of <500 n, N was 0 at the end of. Classification of output per line corresponding integer number.