Chef wants you to write a calculator program for carrying out some simple mathematical operations. Chef calls the program Calculator Plus Plus.

Input

First line contains an operation in the form : a operator b

Output

Output in a single line the result of the mathematical operation. Print "Invalid Operator" if input operator is none of these +, -, *, /

Constraints

-(10^50)<=a,b<=(10^50)

Example
Input:
10 + 30

Output:
40

Input:
1 % 1

Output:
Invalid Operator

Explanation

In first example, 10 + 30 simply evaluates to 40
In second example, '%' is not a valid opeartor according to our Calculator plus plus program.

见题面

见题面