Problem 6: Using any n-bit adders, combinational building blocks, and gates, design a circuit that accepts a three-bit 2s complement binary input a[2:0) and output a six-bit 2's complement output b[5:0] that is seven times the value input. You cannot use a multiplier building block. Use the minimum number of adder bits possible. Problem 6: Using any n-bit adders, combinational building blocks, and gates, design a circuit that accepts a three-bit 2s complement binary input a[2:0) and output a six-bit 2's complement output b[5:0] that is seven times the value input. You cannot use a multiplier building block. Use the minimum number of adder bits possible