Fractions: addition and subtraction - Problems

Two fractions are given. Find their sum or difference.

Input

Each line contains an example of addition or subtraction of fractions. The numerator and denominator of each fraction is a positive integer, not greater than 10⁹.

Output

For each input example, print in a separate line the answer in the form of an irreducible fraction. If the answer is negative, a minus sign in front of the fraction should be printed.

Time limit 1 second

Memory limit 223.37 MiB

Input example #1

1/2 + 3/4
4/5 - 7/3
3/2 + 5/6
7/6 - 1/6
3/2 - 3/2

Output example #1

5/4
-23/15
7/3
1/1
0/1

Author Michael Medvedev