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: def solve(arr, abcd, Q):
      ans = 0
      for i in range(Q):
          if arr[abcd[i][1] - 1] - arr[abcd[i][0] - 1] == abcd[i][2]:
              ans += abcd[i][3]
      return ans
  
  
  N, M, Q = map(int, input().split())
  abcd = []
  for _ in range(Q):
      tmp = list(map(int, input().split()))
      abcd.append(tmp)
  
  ans = 0
  for i1 in range(1, M + 1):
      for i2 in range(1, M + 1):
          if i1 > i2:
              continue
  
          for i3 in range(1, M + 1):
              if i2 > i3:
                  continue
              if N == 3:
                  tmp = [i1, i2, i3]
                  tmp_ans = solve(tmp, abcd, Q)
                  ans = max(tmp_ans, ans)
  
              for i4 in range(1, M + 1):
                  if i3 > i4:
                      continue
                  if N == 4:
                      tmp = [i1, i2, i3, i4]
                      tmp_ans = solve(tmp, abcd, Q)
                      ans = max(tmp_ans, ans)
  
                  for i5 in range(1, M + 1):
                      if i4 > i5:
                          continue
                      if N == 5:
                          tmp = [i1, i2, i3, i4, i5]
                          tmp_ans = solve(tmp, abcd, Q)
                          ans = max(tmp_ans, ans)
  
                      for i6 in range(1, M + 1):
                          if i5 > i6:
                              continue
                          if N == 6:
                              tmp = [i1, i2, i3, i4, i5, i6]
                              tmp_ans = solve(tmp, abcd, Q)
                              ans = max(tmp_ans, ans)
  
                          for i7 in range(1, M + 1):
                              if i6 > i7:
                                  continue
                              if N == 7:
                                  tmp = [i1, i2, i3, i4, i5, i6, i7]
                                  tmp_ans = solve(tmp, abcd, Q)
                                  ans = max(tmp_ans, ans)
  
                              for i8 in range(1, M + 1):
                                  if i7 > i8:
                                      continue
                                  if N == 8:
                                      tmp = [i1, i2, i3, i4, i5, i6, i7, i8]
                                      tmp_ans = solve(tmp, abcd, Q)
                                      ans = max(tmp_ans, ans)
  
                                  for i9 in range(1, M + 1):
                                      if i8 > i9:
                                          continue
                                      if N == 9:
                                          tmp = [i1, i2, i3, i4, i5, i6, i7, i8, i9]
                                          tmp_ans = solve(tmp, abcd, Q)
                                          ans = max(tmp_ans, ans)
  
                                      for i10 in range(1, M + 1):
                                          if i9 > i10:
                                              continue
                                          if N == 10:
                                              tmp = [
                                                  i1,
                                                  i2,
                                                  i3,
                                                  i4,
                                                  i5,
                                                  i6,
                                                  i7,
                                                  i8,
                                                  i9,
                                                  i10,
                                              ]
                                              tmp_ans = solve(tmp, abcd, Q)
                                              ans = max(tmp_ans, ans)
  print(ans)
  
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"}]