Evaluate Mathematical Expression

Given a string s representing a valid mathematical expression, evaluate it and return its integer result. The expression contains non-negative integers, and the operators +, -, *, and /. The division operator should truncate toward zero. The expression may contain whitespace characters, which should be ignored.

For example, using the expression 3+2*2, the result is 7, and for the expression 3-5/2, the result is 1.

Note that the evaluation follows the standard operator precedence: multiplication and division have a higher precedence than addition and subtraction. Formally, the expression is evaluated as per the following rules:

\( \text{result} = \sum_{i} \text{term}_i \), where each term is computed by applying the operators in the correct order.

inputFormat

The input is a single line string representing the mathematical expression.

Input Format:

s

outputFormat

Output a single integer which is the result of evaluating the expression.

Output Format:

result

## sample

3+2*2

7