Bathing problem

A geyser has a capacity of X litres of water and a bucket has a capacity of Y litres of water.

One person requires exactly 2 buckets of water to take a bath. Find the maximum number of people that can take bath using water from one completely filled geyser.
        
       Input:-4
10 6
25 1
100 10
30 40
       Input Description: first line will contain T, number of test cases. Then The test cases follow.
-each test case contains A single line of input, two integers X,Y. 
       Output: 0
12
5
0
       Output Description: For each test case, output the maximum number of people that can take bath. 
       Constraints: 1<=T<=1000
1<=X,Y<=100
       Explanation: Test Case 1: One bucket has a capacity of 6 litres. This means that one person requires 2?6=12 litres of water to take a bath. Since this is less than the total water present in geyser, 0 people can take bath.

Test Case 2: One bucket has a capacity of 1 litre. This means that one person requires 2?1=2 litres of water to take a bath. The total amount of water present in geyser is 25 litres. Thus, 12 people can take bath. Note that 1 litre water would remain unused in the geyser.

Test Case 3: One bucket has a capacity of 10 litres. This means that one person requires 2?10=20 litres of water to take a bath. The total amount of water present in geyser is 100 litres. Thus, 5 people can take bath. Note that 0 litres of water would remain unused in the geyser after this.