Your task is to write an E20 assembler: a program that will convert E20 assembly language into E20 machine language. Each E20 assembly language instruction can be expressed as a 16-bit E20 machine language instruction. The rules for converting between the two forms is given in the E20 manual, particularly the chapter on the E20 instruction set. For example, consider the assembly language instruction addi $1, $2, 3. The opcode is addi, used for performing addition of an immediate. In this case, we are adding the number 3 to the value currently stored in register $2, and storing the result into register $1. The corresponding machine code instruction is 1110100010000011 in binary, or 59523 in decimal, or e883 in hex. Each component of the assembly language instruction maps onto a region of its machine language counterpart.