+ محدودیت زمان: ۶ ثانیه + محدودیت حافظه: ۲۵۶ مگابایت ---------- 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 ```