• محدودیت زمان: ۶ ثانیه
• محدودیت حافظه: ۲۵۶ مگابایت

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Due to heavy snow, George Dantzig was late for his class. When he arrived, his elementary school teacher, Jerzy Neyman had written a homework assignment on the blackboard. It seemed a little harder than usual, but George wrote it down anyway. The assignment was a complex mixture of additions, multiplications and divisions (shown by fractions) on positive numbers; something like the expression below:

\[5 + \frac{4 \times \frac{\frac{5}{7}}{6} }{2 + 3 \times 5} \times 2 + 1 + \frac{1}{1}\]

Every expression or sub-expression has a baseline on which all its elements lie, including operators, numbers, and fraction lines. Obviously, the numerator and denominator of a fraction are respectively placed on top and bottom of its fraction line and they themselves are smaller (possibly complex) sub-expressions. Note that multiplication has a higher priority than addition in evaluating mathematical expressions. Your task is to help George to evaluate the expression as a simple fraction.

ورودی

There are several test cases in the input. Each test case starts with a line containing a single integer \(n\) as the height of the complex expression (\(1 \leq n \leq 60\)). The expression is presented in the next \(n\) lines. Each of these lines has at most \(200\) characters and consists of space characters, consecutive digits as positive numbers, * characters as operators for multiplication, + characters as operators for addition, and consecutive sequences of - characters as fraction lines. If a fraction line is made of \(t\) characters (\(t \geq 3\)), its corresponding numerator and denominator are horizontally aligned within its \(t - 2\) middle characters. Note that there might be some vertical space between a fraction line and its corresponding numerator and/or denominator. Also, the elements of a baseline might be separated by some space characters. Furthermore, some unnecessary spaces at the end of each line may be omitted. The input terminates with a line containing \(0\) which should not be processed.

خروجی

For each test case, print a single line containing the value of the expression in the form of “numerator/denominator”. Note that the numerator and the denominator of each fraction must be coprime, i.e., their greatest common divisor should be \(1\).

مثال

ورودی نمونه ۱

7
       5
      ---
       7           1
   4*-----
       6
5+---------*2+1+ -----
   2+3 *5         1
0

خروجی نمونه ۱

2519/357