C^m(x)=C(C(C(C ... (x))))..., performing C m times. Do this to 9:
9 is odd, C(9)=28.
28 is odd, so C(C(9))=14.
14 is even, so C(C(C(9)))=7.
Continue to get 22,11,34,17,52,26,13,40,20,10,5,16,8,4,2,1
After applying C 19 times, we have reached 1. Therefore, the smallest m is 19.