#11332Summing Digits

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 single 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).

2
11
47
1234567892
0

2
2
2
2