4. Let X-a, b and Y-1, 2, none, both. Construct a Mealy machine that outputsa 1 if the number of a's in the input string (mod 4) is equal to 2, outputs a 2 if the number of b's in the input string (mod 3) is equal to 1, and outputs "both" if both conditions are true. If neither condition is true it outputs "none." If such a Mealy machine does not exist indicate why not