1. Design a Full Adder using 2x4 Decoders and any other additional AND/OR/NOT gates if needed. Use the component symbol below when designing the full adder. Decoder -o, 2. Design a minimum-cost circuit that accepts as inputs two 2-bit unsigned binary integers, A Ao and B1Bo, and outputs their difference, calculated as A1Ao B1Bo, in signed one's complement format. The output should always use the same signed one's complement representation for the number zero (i.e., all 1s or all 0s). Draw circuit diagrams for each output bit. Provide evidence that your design minimizes the cost of calculating each output bit