Given a string s that represents a mathematical expression that consists of numbers and basic operations (+-*/), you are asked to calculate the value of the expression.
All the numbers are guaranteed to be smaller than 10000 by their absolute value. Using eval is not allowed.
Input
The input contains a single line representing s (1 ≤ |s| ≤ 1000).
Output
The program should print the resulting value of the expression.