E: Internet Service Providers
-----------------------------

A group of N Internet Service Provider companies (ISPs) use a 
private communication channel that has a maximum capacity of 
C traffic units per second.  Each company transfers T traffic 
units per second through the channel and gets a profit that is 
directly proportional to the factor T(C - T N).  The problem is 
to compute T_optim, the smallest value of T that maximizes the 
total profit the N ISPs can get from using the channel.  Notice 
that N, C, T, and T_optim are integer numbers.

Input
-----
The input consists of multiple data sets.  Each data set corresponds 
to an instance of the problem above and consists of a single line
containing two integer numbers, N and C, with values in the range 
from 0 to 109.  N and C are separated by white spaces and are 
correct.  The input is terminated by 0 0 (this data set should not
be considered). 

Output
------
For each data set the program computes the value of T_optim according 
to the problem instance that corresponds to the data set.  The result 
is printed.  There must be no empty lines on the output.

Sample Input
------------
1 0
0 1
4 3
2 8
3 27
25 1000000000
0 0

Sample Output
-------------
0
0
0
2
4
20000000