Definition: In this task you will be given a list, of lists, of integers. For every inner list contained in the input list, you should multiply every even number in that list. The output should be a list of integers with the same length as the number of lists in the input list. If there are no even numbers in an inner list you should output 0 for that list.
Input: [[-40, 15, -31], [-36, 41, 2, 9, -49], [8, -6, 42, -47], [21, -31, 41, -32, 18]]
Output:
[-40, -72, -2016, -576]