A digital computer has 32-bit instructions. There are a number ofdifferent instruction formats, and the number of bits in eachformat used for opcodes varies depending on the bits needed forother fields. If the first bit of the opcode is 0, then there arethree opcode bits. If the first bit of the opcode is 1 and thesecond bit of the opcode is 0, then there are six opcode bits. Ifthe first bit of the opcode is 1 and the second of the opcode is 1,then there are nine opcode bits. How many distinct opcodes areavailable for this computer?