input: Write a function to add a given integer mark to each element in a list of marks. The function will be called add_marks and will take two parameters: marks (a list) and mark (an integer). It should return a new list where each element is the sum of the original element and the given mark.
  
  assert add_marks([87, 56, 99, 54], 4) == [91, 60, 103, 58]
  assert add_marks([72, 80, 65], 2) == [74, 82, 67]
  assert add_marks([10, 20, 30], 5) == [15, 25, 35]
  assert add_marks([], 1) == []
  assert add_marks([90, 91, 92], 0) == [90, 91, 92]
output: def add_marks(marks, mark):
      return [x + mark for x in marks]