R1 -> 17 1 20 12 $Array = [17,1,20,12] $Array[0] ->first track ... #### R1 -> 17 1 20 12 R2 -> 4 R1 -> 21 13 24 4 17 21 1 13 20 24 12 R2-> 6 R1 -> 19 30 31 27 4 6 17 21 27 1 13 19 20 24 30 12 31 R2-> 3 R1 -> 22 34 4 6 3 17 21 27 1 13 19 22 20 24 30 12 31 34 ... ...