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, p = map(int, input().split())
  A = []
  B = []
  C = []
  D = []
  maximum = 0
  for i in range(p):
      a, b, c, d = map(int, input().split())
      A.append(a)
      B.append(b)
      C.append(c)
      D.append(d)
  for z in range(m):
      for y in range(z, m):
          if n > 2:
              for x in range(y, m):
                  if n > 3:
                      for w in range(x, m):
                          if n > 4:
                              for v in range(w, m):
                                  if n > 5:
                                      for u in range(v, m):
                                          if n > 6:
                                              for t in range(u, m):
                                                  if n > 7:
                                                      for s in range(t, m):
                                                          if n > 8:
                                                              for r in range(s, m):
                                                                  if n > 9:
                                                                      for q in range(
                                                                          r, m
                                                                      ):
                                                                          L = [
                                                                              z,
                                                                              y,
                                                                              x,
                                                                              w,
                                                                              v,
                                                                              u,
                                                                              t,
                                                                              s,
                                                                              r,
                                                                              q,
                                                                          ]
                                                                          a = 0
                                                                          for l in range(
                                                                              p
                                                                          ):
                                                                              if (
                                                                                  L[
                                                                                      B[l]
                                                                                      - 1
                                                                                  ]
                                                                                  - L[
                                                                                      A[l]
                                                                                      - 1
                                                                                  ]
                                                                                  == C[l]
                                                                              ):
                                                                                  a += D[
                                                                                      l
                                                                                  ]
                                                                          maximum = max(
                                                                              maximum, a
                                                                          )
                                                                  else:
                                                                      L = [
                                                                          z,
                                                                          y,
                                                                          x,
                                                                          w,
                                                                          v,
                                                                          u,
                                                                          t,
                                                                          s,
                                                                          r,
                                                                      ]
                                                                      a = 0
                                                                      for l in range(p):
                                                                          if (
                                                                              L[B[l] - 1]
                                                                              - L[
                                                                                  A[l] - 1
                                                                              ]
                                                                              == C[l]
                                                                          ):
                                                                              a += D[l]
                                                                      maximum = max(
                                                                          maximum, a
                                                                      )
                                                          else:
                                                              L = [z, y, x, w, v, u, t, s]
                                                              a = 0
                                                              for l in range(p):
                                                                  if (
                                                                      L[B[l] - 1]
                                                                      - L[A[l] - 1]
                                                                      == C[l]
                                                                  ):
                                                                      a += D[l]
                                                              maximum = max(maximum, a)
                                                  else:
                                                      L = [z, y, x, w, v, u, t]
                                                      a = 0
                                                      for l in range(p):
                                                          if (
                                                              L[B[l] - 1] - L[A[l] - 1]
                                                              == C[l]
                                                          ):
                                                              a += D[l]
                                                      maximum = max(maximum, a)
                                          else:
                                              L = [z, y, x, w, v, u]
                                              a = 0
                                              for l in range(p):
                                                  if L[B[l] - 1] - L[A[l] - 1] == C[l]:
                                                      a += D[l]
                                              maximum = max(maximum, a)
                                  else:
                                      L = [z, y, x, w, v]
                                      a = 0
                                      for l in range(p):
                                          if L[B[l] - 1] - L[A[l] - 1] == C[l]:
                                              a += D[l]
                                      maximum = max(maximum, a)
                          else:
                              L = [z, y, x, w]
                              a = 0
                              for l in range(p):
                                  if L[B[l] - 1] - L[A[l] - 1] == C[l]:
                                      a += D[l]
                              maximum = max(maximum, a)
                  else:
                      L = [z, y, x]
                      a = 0
                      for l in range(p):
                          if L[B[l] - 1] - L[A[l] - 1] == C[l]:
                              a += D[l]
                      maximum = max(maximum, a)
          else:
              L = [z, y]
              a = 0
              for l in range(p):
                  if L[B[l] - 1] - L[A[l] - 1] == C[l]:
                      a += D[l]
              maximum = max(maximum, a)
  print(maximum)
  
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"}]