Design an adder for excess-3 decimal digits (see Table 1-2) using a ROM. Add two excess-3 digits and give the excess-3 sum and a carry. For example, 1010+1001=0110 with carry of 1(7+6=13). Draw a block diagram showing the required ROM inputs and outputs. What size ROM is required? Indicate how the truth table for the ROM would be specified by giving some typical rows.