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 = map(int, input().split())
  
  a = [0 for _ in range(Q + 1)]
  b = [0 for _ in range(Q + 1)]
  c = [0 for _ in range(Q + 1)]
  d = [0 for _ in range(Q + 1)]
  
  for i in range(1, Q + 1):
      a[i], b[i], c[i], d[i] = map(int, input().split())
  
  
  def asc(x):
      y = sorted(x)
      return list(x) == y
  
  
  def cond(p, i):
      if asc(p):
          try:
              if p[b[i]] - p[a[i]] == c[i]:
                  # print(p)
                  # print('{}-{}={} | d={}'.format(p[a[i]],p[b[i]],c[i],d[i]))
                  return d[i]
          except IndexError:
              return 0
      return 0
  
  
  import itertools
  
  lisM = list(range(1, M + 1))
  print(lisM)
  p = itertools.permutations(lisM, N + 1)
  D = []
  for x in p:
      for i in range(1, Q + 1):
          D += [cond(x, i)]
  
  print(max(D))
  
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"}]