按照四则运算加、减、乘、除、幂（^）和括号的优先关系和惯例，编写计算器程序。

①　　从键盘输入一个完整的表达式，以’#’作为表达式输入结束的标志。

②　　输入表达式中的数值均为大于等于零的整数。中间的计算过程如果出现小数也只取整。

-In accordance with the arithmetic addition, subtraction, multiplication, division, power (^) and the parentheses precedence relations and practices, the preparation of the calculator program. ① from the keyboard to enter a complete expression, in order to ' #'　as the input signal the end of the expression. ② Enter the expression values ??are integers greater than zero. The middle of the computation process only if there is decimal rounding.