But there are many other ways to do this. For example, one can do the same first step (raise three fingers on one's left hand), and then start counting from 4 as one raises four more fingers one at a time on either the right hand, or even starting from the fourth finger on the left hand (which would require continuing from 6 on the right hand). Different strategies may have very different characteristics in terms of their time and space complexity, memory requirements, etc., and therefore in terms of their error characteristics.