output_description: Print the maximum possible score of A.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      N M Q
      a_1 b_1 c_1 d_1
      :
      a_Q b_Q c_Q d_Q
attempt: n, m, q = list(map(lambda x: int(x), input().split(" ")))
  
  e = []
  
  for i in range(q):
      s = list(map(lambda x: int(x), input().split(" ")))
      e.append(s)
  
  
  def helper(l, tmp, n, all):
      if len(tmp) == n:
          r = tmp.copy()
          all.append(r)
          return
  
      for i, v in enumerate(l):
          tmp.append(v)
          helper(l[i:], tmp, n, all)
          tmp.pop()
  
  
  candidates = []
  helper(list(range(1, m + 1)), [], n, candidates)
  
  max_val = 0
  
  for c in candidates:
      sum = 0
  
      for j in e:
          if c[j[1] - 1] - c[j[0] - 1] == j[2]:
              sum += j[3]
  
      max_val = max(max_val, sum)
  
  print(max_val)
  
problem_description: Statement
  
  Given are positive integers N, M, Q, and Q quadruples of integers ( a_i , b_i
  , c_i , d_i ).
  
  Consider a sequence A satisfying the following conditions:
  
    * A is a sequence of N positive integers.
    * 1 \leq A_1 \leq A_2 \le \cdots \leq A_N \leq M.
  
  Let us define a score of this sequence as follows:
  
    * The score is the sum of d_i over all indices i such that A_{b_i} - A_{a_i} = c_i. (If there is no such i, the score is 0.)
  
  Find the maximum possible score of A.
samples: [{"input": "3 4 3\n    1 3 3 100\n    1 2 2 10\n    2 3 2 10", "output": "110\n    \n\nWhen A = \\\\{1, 3, 4\\\\}, its score is 110. Under these conditions, no sequence\nhas a score greater than 110, so the answer is 110.\n\n* * *"}, {"input": "4 6 10\n    2 4 1 86568\n    1 4 0 90629\n    2 3 0 90310\n    3 4 1 29211\n    3 4 3 78537\n    3 4 2 8580\n    1 2 1 96263\n    1 4 2 2156\n    1 2 0 94325\n    1 4 3 94328", "output": "357500\n    \n\n* * *"}, {"input": "10 10 1\n    1 10 9 1", "output": "1"}]