An adder for Gray-coded-decimal digits is to be designed using a ROM. The adder should add two gray-coded digits and give the Gray-coded sum and a carry. For example, 1011 +1010=0010 with a 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.