1. The problem statement, all variables and given/known data Construct a finite-state machine that changes every other bit, starting with the second bit, of an input string, and leaves the other bits unchanged. 2. Relevant equations - 3. The attempt at a solution Say I have the string 1001101, then I am supposed to make a finite-state machine that turns it into 1100111 (every other bit changed, starting from the 2nd). I know how to change the bits in a machine, what I need help for is how to determine the index of the input, that is how to let the finite-state machine know i.e. that 0 which happens to be the second bit of the string, is in fact the second. Thanks.