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 PyPy3 (7.3.0) (judge verdict: Accepted)

#!/usr/bin/env python3
import sys
import itertools

def solve(N: int, M: int, Q: int, a: "List[int]", b: "List[int]", c: "List[int]", d: "List[int]"):
    result = 0
    for iter in itertools.combinations_with_replacement(range(1,M+1),N):
        l = sorted(list(iter))
        sum = 0
        for i in range(Q):
            if l[b[i]-1] - l[a[i]-1] == c[i]:
                sum += d[i]
        result = max(result,sum)
    print(result)
    return


# Generated by 1.1.6 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    M = int(next(tokens))  # type: int
    Q = int(next(tokens))  # type: int
    a = [int()] * (Q)  # type: "List[int]"
    b = [int()] * (Q)  # type: "List[int]"
    c = [int()] * (Q)  # type: "List[int]"
    d = [int()] * (Q)  # type: "List[int]"
    for i in range(Q):
        a[i] = int(next(tokens))
        b[i] = int(next(tokens))
        c[i] = int(next(tokens))
        d[i] = int(next(tokens))
    solve(N, M, Q, a, b, c, d)

if __name__ == '__main__':
    main()