Write a program in LEGv8 assembly to convert an ASCII string containing a positive or negative integer decimal string to an integer. Your program should expect register X0 to hold the address of a null-terminated string containing an optional '+' or '-', followed by some combination of the digits 0 through 9. Your program should compute the integer value equivalent of this string of digits, then place the number in register X0. If a non-digit character appears anywhere in the string, your program should stop with the value -1 in register X0. For example, if register X0 points to a sequence of three bytes 50, 52, 0 (the null-terminated string "24"), then when the program stops, X0 should contain the value 24. Remember that, the MUL instruction takes two registers as input, and there is no "MULI" instruction.