在字节数组中找出第一个负数，并将该负数存入RES单元中；假设该数组中包含20个带符号数，且至少有1个负数（要求在debug中调试出该程序）-20 with the number of symbols to identify the first negative number in the byte array, and the negative deposit the RES unit　assumptions contained in the array, and at least one negative (requires debugging the program in debug)