The digits 3 and 9 share an interesting property. If you take any multiple of 3and sum its digits, you get another multiple of 3. For example 3 * 118 = 354 and 3 + 5 + 4 = 12, which is a multiple of 3. Similarly, if you take any multiple of 9 and sum its digits, you get another multiple of 9. A digit that is interesting in one base(진법) is not necessarily interesting in another base. For example,..
