Smeech#6672
Professor Octastichs has invented a new programming language, Smeech. An expression in Smeech may be a positive or negative integer, or may be of the form (p\ e_1\ e_2) where is a real number between and (inclusive) and e_1 and e_2 are Smeech expressions. The value represented by a Smeech expression is as follows:
An integer represents itself
With probability , (p\ e_1\ e_2) represents x + y where is the value of e_1 and is the value of e_2; otherwise it represents x - y.
Given a Smeech expression, what is its expected value?
Consists of several Smeech expressions, one per line, followed by a line containing . The final line containing is not processed.
For each expression, output its expected value to two decimal places.
Example 1