从键盘输入两个十六进制数（长度小于4），计算它们的和然后输出,如输入的两个数为1111，abcd,则显示结果为:1111+abcd=bcde-Keyboard input from the two hexadecimal digits (the length is less than 4), and then calculate their output, such as the importation of the two number 1111, abcd, then the result will be displayed for: 1111+ Abcd = bcde