数根

　　数也有根吗？有！数根就是把一个数的各个数位上的值相加，直到得到一个一位数为止。请你编写一个程序来计算任意数N（0≤N≤1000000000000）的根。

　　

输入：

输入有多个案例。每一个案例为一行，每行只有一个整数N。当输入的N是-1时，输入结束。

输出：

每一个案例输出一行。每行只有一个数字，就是N对应的数根。



Sample input

39

-1

Sample output

3-Number of root number also has roots do? There is! The number of roots is to a number of different values on the digital sum until they have been a number of up to one. Please write a program to calculate an arbitrary number N (0 ≤ N ≤ 1000000000000) roots. Input: Enter a number of cases. Each case for the line, each line is only an integer N. When the input of N is-1, the input end. Output: the output line of each case. There is only one number per line, that is, N corresponds to the number of roots. Sample input 39-1 Sample output 3