Label all the inputs and outputs for the circuit below and add wires, as necessary, so that the circuit as a whole contains a 2's complement integer adder. The labels A3, A2, A1, A0 are the four bits of operand A from MSB to LSB. Maintain this order of placement for all your labels. The circuit inputs enter at the top and right sides of the devices. Outputs exit each device box symbol at the bottom and left. The resulting circuit must perform A+B and A-B depending on the assertion of the input Subtract.
Negation circuit
A3
A2
A1
A0
C_out 4-bit Ripple-Carry Adder from Full Adders
C_in