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 - TN). 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.

Each data set corresponds to an instance of the problem above and contains two integral numbers – N and C – with values in the range from 0 to 10⁹. The input data are separated by white spaces, are correct, and terminate with an end of file.

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 on the standard output from the beginning of a line. There must be no empty lines on the output.

1 0 
0 1 
4 3 
2 8 
3 27 
25 1000000000

0 
0 
0 
2 
4 
20000000