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 Rust (1.42.0) (judge verdict: Accepted)

use proconio::input;

fn main() {
    input! {
        n: usize,
        m: usize,
        q: usize,
        abcds: [(usize, usize, usize, usize); q],
    };
    // dbg!(M,N,Q);
    // dbg!(abcds);
    let mut max = 0;
    let mut nums = vec![1; n];
    while {
        let sum = calc(&nums, &abcds);
        if sum > max {
            max = sum;
        }
        next(&mut nums, &m)
    } {}
    println!("{}", max);
}

fn calc(nums: &Vec<usize>, abcds: &Vec<(usize, usize, usize, usize)>) -> usize {
    let mut sum = 0;
    for &(a, b, c, d) in abcds {
        if nums[b - 1] - nums[a - 1] == c {
            sum += d;
        }
    }
    sum
}

fn next(nums: &mut Vec<usize>, m: &usize) -> bool {
    // 右から9のindexを探す
    // ある → 一番左にあるmの左隣をインクリメントし右を全部それに
    // ない → 右端を+1
    let len = nums.len();
    let ii = nums.iter().position(|x| x == m);
    if let Some(i) = ii {
        if i == 0 {
            return false;
        } else {
            nums[i - 1] += 1;
            for j in i..len {
                nums[j] = nums[i - 1];
            }
        }
    } else {
        nums[len - 1] += 1;
    }
    true
}