output_description: Print the maximum possible sum of the chosen elements.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N
      A_1 ... A_N
attempt: s = [input() for i in range(2)]
  s[1] = s[1].split(" ")
  n = 0
  j = 0
  for k in s[1]:
      m = int(k)
      if m % 2 == 0:
          j += m
      if m % 2 != 0:
          n += m
  if n < j:
      print(j)
  else:
      print(n)
  
problem_description: Statement
  
  Given is an integer sequence A_1, ..., A_N of length N.
  
  We will choose exactly \left\lfloor \frac{N}{2} \right\rfloor elements from
  this sequence so that no two adjacent elements are chosen.
  
  Find the maximum possible sum of the chosen elements.
  
  Here \lfloor x \rfloor denotes the greatest integer not greater than x.
samples: [{"input": "6\n    1 2 3 4 5 6", "output": "12\n    \n\nChoosing 2, 4, and 6 makes the sum 12, which is the maximum possible value.\n\n* * *"}, {"input": "5\n    -1000 -100 -10 0 10", "output": "0\n    \n\nChoosing -10 and 10 makes the sum 0, which is the maximum possible value.\n\n* * *"}, {"input": "10\n    1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 1000000000", "output": "5000000000\n    \n\nWatch out for overflow.\n\n* * *"}, {"input": "27\n    18 -28 18 28 -45 90 -45 23 -53 60 28 -74 -71 35 -26 -62 49 -77 57 24 -70 -93 69 -99 59 57 -49", "output": "295"}]