Two friends Kunal and Satyam are playing an interesting game. They take turns drawing a ball from a bag which initially contains R red balls and G green balls. Each player draws a ball alternatively and never put it back. The person who is the first to draw a red balls wins. Satyam always draws first. If there are no more balls in the bag and nobody has drawn a red ball, the satyam wins.
What is the probability of the Satyam winning?
Input:
The first line will contain the number of test cases T.
The first line of each test case will contain a number R (number of red balls) and G(number of green balls )
Output
For each testcase, print the desired probability.
Constraints:
1<=T<=10
0<=R,G<=10^3
Problem Setter : Surya Pratap Singh