TASK DEFINITION: In this task you will be given a list, of lists, of numbers. Each list is presented with brackets and comma-separated values. For example, a list of numbers is [1,2,3] and a list of two lists of numbers is [[1,2],[3,4,6]]. You should sum up the values at every position of every inner list and put it as an element of your answer, that is, you should sum the first members of each inner list together and put it as the first element of the list, then sum the second members of each inner list together and put it as the second element of your list, etc. The output should be a list of numbers with the same length as the longest inner list.
PROBLEM: [[77, -51], [-62, -87, 99], [21, -45, -79, 46, 88, -75, 31], [19, -28, 84, -1, 45, -67]]

SOLUTION: [55, -211, 104, 45, 133, -142, 31]

PROBLEM: [[-47, 90, 95, 31, 55, -36, -97, -13], [-86, 72], [13, -1, 85, -100]]

SOLUTION: [-120, 161, 180, -69, 55, -36, -97, -13]

PROBLEM: [[77, 55, -36, 4, -8, 84, -26, 13, -83], [21, 80, 21, 78], [42, -6, -48, 38], [31, -9, -25, -1, -55, 82], [78, 58, 85, -97, -77, -41, -90, 50, 10]]

SOLUTION:
[249, 178, -3, 22, -140, 125, -116, 63, -73]