For a positive integer n, let f(n) denote the sum of the digits of n when represented in base 10. It is easy to see that the sequence of numbers n, f (n), f (f (n)), f (f (f (n))), . . . eventually becomes a single digit number that repeats forever. Let this sin- gle digit be denoted g(n). For example, consider n = 1234567892. Then: f (n) = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 2 = 47 f(f(n)) = 4 + 7 = 11 f(f(f(n))) = 1 + 1 = 2 Therefore, g(1234567892) = 2. Input Each line of input contains a single positive integer n at most 2,000,000,000. Input is terminated by n = 0 which should not be processed. Output For each such integer, you are to output a single line containing g(n). Sample Input 2 11 47 1234567892 0 Sample Output 2 2 2 2