Title Description
The so-called postfix expression refers to an expression: where no longer referenced after two operations on objects in order to calculate all arithmetic symbols appear, from left to right strict new conduct (regardless of the operation parentheses, arithmetic symbols precedence).
Such as: 3 (5-2) corresponding to the postfix expression is +7: 3.5.2. - 7 + @. '@' Symbol for the end of the expression. '.' End symbol operand.
Input Format
Input: a string representing the postfix expression. (String length not exceeding 1000)
Output Format
Output: The value of the expression.
Sample input
3.5.2.-*7.+@Sample Output
16