You are to design a 4-bit adder/subtractor. The circuit receives two four bit numbers A=A3A₂A₁A0 and B=B3B₂B₁B₁. Depending upon the value of control input, the circuit produces A+B or A-B. Subtraction can be performed by adding two's complement of Bto A. The output, along with any carry and sign bit, should be in un-complemented form. 1. Design the circuit. 2. Draw the complete layout of the circuit. 3. Simulate the circuit and show that the circuit works. 4. Submit a neat and readable report with all the computer outputs properly attached andexplained.