Your task is to write a program, which implements addition, subtraction, multiplication and division operations on fractions.
Input and output fraction format is as follows:
 the sign of a number (must be written only if its absence may lead to misrepresentation of the number),
 the integer part of a number (the integer part that equals zero must be omitted if the numerator and the denominator are present),
 a space character (must be omitted if the integer or fractional part is absent),
 the numerator (if it is not equal to zero),
 the “/” sign (written only if there is a numerator),
 the denominator (must be omitted if there is no numerator),
 the denominator cannot be equal to zero.
Samples of fractional number representation: “7 3/4”, “8 1/2”, “7/11”, “0”, “11”.
Limitations
All limitations apply for both input and output data.
The sign of a fraction: if the fraction is positive, the sign is not written; if the fraction is negative, the “” sign must be present.
The integer part and the numerator may have values ranging from 0 to 30000, the denominator may have values from 1 to 30000.
The operation sign may be one of the four possible symbols: “+” (addition), “” (subtraction), “*” (multiplication), “/” (division).
The expression is always correct, so the second operand in the division operation cannot be zero.
Input
The first line – a fraction (the first operand);
The second line – the sign of an operation;
The third line – a fraction (the second operand).
Both fractions may be reducible. The numerator is always less than the denominator.
Output
A single line that contains an irreducible proper fraction (result) in the format described above.
Sample
input  output 

3 1/6
+
2/4
 2 2/3

Problem Author: © Sergey G. Volchenkov, 2003(volchenkov@yandex.ru); Vladimir N. Pinaev, 2003(vpinaev@mail.ru; http://www.pic200x.chat.ru); Michael Y. Kopachev, 2003 (mkopachev@krista.ru).
Problem Source: 20032004 ACM Central Region of Russia Quarterfinal Programming Contest, Rybinsk, October 1516, 2003