数据打包。按照一定的格式输入一个函数表达式，程序自动检测输入的函数是否正确。如果正确，则进行打包；如果不正确，则重新输入。-The data package. Enter a function expression, according to a certain format, the program automatically detects whether the input function correctly. If this is correct, then the package　If this is not correct, then re-enter.