9170번 - Single Digit Adder 다국어

Write a program that can evaluate expressions from the following roughly BNF (Backus Naur Form) grammar:

expr ::=  term | expr ‘+’ term | expr ‘-’ term
unary_op ::= ‘+’ term | ‘-’ term
term ::= ‘(’ expr ‘)’ | ‘(’ unary_op ‘)’ | literal
literal ::= [0-9]

There will be no whitespace within an expression. All expressions will consist solely of the characters (, ), +, -, and the digits 0 through 9. You may assume that all input is well-formed.

The input will consist of one expression per line followed by a newline. The length of expression does not exceed 200.

There will be no blank lines in the file.

For each expression, output its integer value, followed by a single newline.