Using half-adders and full-adders as a block together with external gates, design the following circuit in the most efficient way possible A)S = A + B - C +D (A, B, C and D are 3-bit numbers and should be represented as A2A1A0, B2B1B0, C2c1co and D2D1DO) B)S = K - L + M - N (K, L, M and N are 3-bit numbers and should be represented as K2K1K0, L2L1LO, M2M1MO and N2N1N0)| Using half-adders and full-adders as a block together with external gates, design the following circuit in the most efficient way possible A)S = A + B - C +D (A, B, C and D are 3-bit numbers and should be represented as A2A1A0, B2B1B0, C2c1co and D2D1DO) B)S = K - L + M - N (K, L, M and N are 3-bit numbers and should be represented as K2K1K0, L2L1LO, M2M1MO and N2N1N0)|