#include <stdio.h>
#include <string.h>

int next_seq(int *seq, const int len, const int m)
{
    int carry = 0, last, last_value;
    for (int i = len - 1; i >= 0; i--)
    {
        if (seq[i] >= m && i > 0)
        {
            seq[i] = seq[i - 1] + 1;
        }
        else if (seq[i] >= m)
        {
            carry = 1;
        }
        else
        {
            seq[i]++;
            last = i;
            last_value = seq[i];
            break;
        }
    }

    for (int i = last + 1; i < len; i++)
    {
        seq[i] = last_value;
    }

    return carry;
}

int main()
{
    int n, m, q, max = 0;
    int a[50] = {
        0,
    };
    int b[50] = {
        0,
    };
    int c[50] = {
        0,
    };
    int d[50] = {
        0,
    };

    int seq[11] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};

    scanf("%d %d %d", &n, &m, &q);
    for (int i = 0; i < q; i++)
    {
        scanf("%d %d %d %d", &a[i], &b[i], &c[i], &d[i]);
    }

    seq[n - 1] = 0;

    while (!next_seq(seq, n, m))
    {
        int sum = 0;

        for (int i = 1; i <= q; i++)
        {
            if (seq[b[i - 1] - 1] - seq[a[i - 1] - 1] == c[i - 1])
                sum += d[i - 1];
        }
        /*
        for (int i = 0; i < n; i++)
        {
            printf("%02d ", seq[i]);
        }
        */
        max = max < sum ? sum : max;
        //printf(" %d\n", sum);
    }

    printf("%d", max);

    return 0;
}