input: Write a function to find the maximum sum of points in any subpolygon of four points.
  assert max_subpolygon_sum(4, [(1, 2), (3, 4), (5, 6), (7, 8)]) == 15
  assert max_subpolygon_sum(5, [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]) == 14
  assert max_subpolygon_sum(4, [(1, 1), (1, 1), (1, 1), (1, 1)]) == 4
output: def max_subpolygon_sum(n, points):
      if n < 4:
          return 0
  
      max_sum = 0
      for i in range(n):
          for j in range(i + 1, n):
              for k in range(j + 1, n):
                  for l in range(k + 1, n):
                      current_sum = points[i][1] + points[j][1] + points[k][1] + points[l][1]
                      max_sum = max(max_sum, current_sum)
  
      return max_sum