Implement a function that orders inputs to schedule for min TAT(turn around time)
Input(list of runtimes,number of parallel buckets)

For example,

1.Input: [4,3,100,2,1] parallel = 2

Output: [[100],[4,3,2,1]] TAT= 100

2.Input [4,3,1,2] parallel = 2

Out [[4,1],[3,2]] TAT = 5