Problem:
Score : 300 points

Problem 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.

Constraints

All values in input are integers.

2 ≤ N ≤ 10

1 \leq M \leq 10

1 \leq Q \leq 50

1 \leq a_i < b_i \leq N ( i = 1, 2, ..., Q )

0 \leq c_i \leq M - 1 ( i = 1, 2, ..., Q )

(a_i, b_i, c_i) \neq (a_j, b_j, c_j) (where i \neq j)

1 \leq d_i \leq 10^5 ( i = 1, 2, ..., Q )

Input

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

Output

Print the maximum possible score of A.

Sample Input 1

3 4 3
1 3 3 100
1 2 2 10
2 3 2 10

Sample Output 1

110

When A = \{1, 3, 4\}, its score is 110. Under these conditions, no sequence has a score greater than 110, so the answer is 110.

Sample Input 2

4 6 10
2 4 1 86568
1 4 0 90629
2 3 0 90310
3 4 1 29211
3 4 3 78537
3 4 2 8580
1 2 1 96263
1 4 2 2156
1 2 0 94325
1 4 3 94328

Sample Output 2

357500

Sample Input 3

10 10 1
1 10 9 1

Sample Output 3

1

Solution in Lua (LuaJIT 2.1.0) (judge verdict: Accepted)

local mmi, mma = math.min, math.max
local mfl, mce = math.floor, math.ceil
local n, m, q = io.read("*n", "*n", "*n")
local t = {}
for iq = 1, q do
  local a, b, c, d = io.read("*n", "*n", "*n", "*n")
  t[iq] = {a, b, c, d}
end

local function combination_get_map(n)
  local combmap = {}
  for i = 1, n do
    combmap[i] = {}
    local ret = 1
    for j = 1, i do
      ret = mfl(ret * (i + 1 - j) / j)
      combmap[i][j] = ret
    end
  end
  return combmap
end
local function combination_get_count(combmap, n, k)
  if k < 0 then return 0
  elseif n < k then return 0
  elseif k == 0 then return 1
  else return combmap[n][k]
  end
end

local function combination_get_array(combmap, n, k, idx)
  local rem = k
  local retary = {}
  for i = 1, n do
    local useCnt = combination_get_count(combmap, n - i, rem - 1)
    local unuseCnt = combination_get_count(combmap, n - i, rem)
    if idx <= useCnt then
      rem = rem - 1
      table.insert(retary, i)
    else
      idx = idx - useCnt
    end
  end
  return retary
end

local combmap = combination_get_map(n + m - 1)
local combcnt = combination_get_count(combmap, n + m - 1, n)
local ans = 0
for i = 1, combcnt do
  local ary = combination_get_array(combmap, n + m - 1, n, i)
  for j = 1, n do
    ary[j] = ary[j] - j + 1
  end
  local r = 0
  for iq = 1, q do
    local a, b, c, d = unpack(t[iq])
    if ary[b] - ary[a] == c then
      r = r + d
    end
  end
  ans = mma(ans, r)
end
print(ans)