Given M lists of variable length where every element in each list is sorted, print them out in sorted order efficiently.
Input: Four sorted lists of variable length
[32, 33],
[10, 20, 30, 40],
[15, 25, 35],
[27, 29, 37, 48, 93]
Output:
10, 15, 20, 25, 27, 29, 30, 32, 33, 35, 37, 40, 48, 93