Design a 4-bit adder-subtractor circuit using the 4-bit binaryFull adders (74LS83) and any necessary additional logic gates. Thecircuit has a mode input bit, M, that controls its operation.Specifically, when M=0, the circuit becomes a 4-bit adder, and whenM=1, the circuit becomes a 4-bit subtractor that performs theoperation A plus the 2’s complement of B.Where A and B are two4-bits binary numbers. That is,

* When M=0, we perform A+B, and we assumethat both numbers are unsigned numbers. So the maximum sum valuewill be 15 (since we are assuming A and B are 4-bit numbers).

* When M=1, we perform A+ (B)2’sComplement. That is, we find first the2’s complement of B then addit to A. Hence, here the answer of theoperation A-B is expressed in2’s complement representation.

* In both cases above, assume that overflow willnot happen. That is, you may assume that your inputs are chosen ina way that willnot generate overflow. So, youdon’t have to worry aboutoverflow.

a. Draw the logic diagram that implements this circuit,andsimulate the circuit on logisim program.

**please show details of your work