new_contents: """Maximum path sum I
  
  By starting at the top of the triangle below and moving to adjacent numbers on
  the row below, the maximum total from top to bottom is 23.
  
  [3]
  [7] 4
  2 [4] 6
  8 5 [9] 3
  
  That is, 3 + 7 + 4 + 9 = 23.
  
  Find the maximum total from top to bottom of the triangle below:
  
  75
  95 64
  17 47 82
  18 35 87 10
  20 04 82 47 65
  19 01 23 75 03 34
  88 02 77 73 07 63 67
  99 65 04 28 06 16 70 92
  41 41 26 56 83 40 80 70 33
  41 48 72 33 47 32 37 16 94 29
  53 71 44 65 25 43 91 52 97 51 14
  70 11 33 28 77 73 17 78 39 68 17 57
  91 71 52 38 17 14 91 43 58 50 27 29 48
  63 66 04 68 89 53 67 30 73 16 69 87 40 31
  04 62 98 27 23 09 70 98 73 93 38 53 60 04 23
  
  Note: As there are only 16384 routes, it is possible to solve this problem by
  trying every route. However, Problem 67, is the same challenge with a triangle
  containing one-hundred rows; it cannot be solved by brute force, and requires
  a clever method!
  """
  
subject: Add problem statement 18