A BCD counter produces a $4-$bit output representing the BCD code for the number of pulses that have been applied to the counter input. For example, after four pulses have occurred, the counter outputs are DCBA $=01002=410.$ The counter resets to $0000$ on the tenth pulse and starts counting over again. In other words, the DCBA outputs will never represent a number greater than $10012$ or $910.$ Design the logic circuit that produces a HIGH output whenever the count is $2,3,$ or $9.$ The simplified equation is $\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$