Simple Expression Evaluator

You are given a mathematical expression as a string expr consisting only of positive integers, and the operators + and -. Your task is to evaluate the expression and print the result.

The expression follows the format:

\(expr = number \; ( ( '+' | '-' ) \; number )^*\)

For example, when expr = "12+34-5+6", the output should be 47. The expression is guaranteed to be valid and does not contain any spaces.

inputFormat

The input consists of a single line containing a non-empty string expr which represents the mathematical expression. The expression contains only digits (0-9) and the operators '+' and '-'.

outputFormat

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

12+34-5+6

47