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 (Python):
def main(sample_file = ''):

    """ convenient functions
    
    
    
    
    
    """

    """convenient decorator
    
    
        
        
        
        
        
        
        
        
        
        
    """
    
    
    import sys
    sys.setrecursionlimit(10**7)
    from itertools import accumulate, combinations, permutations, product 
    
    from math import factorial, ceil, floor, sqrt
    def factorize(n):
        """return the factors of the Arg and count of each factor
        
        Args:
            n (long): number to be resolved into factors
        
        Returns:
            list of tuples: factorize(220) returns [(2, 2), (5, 1), (11, 1)]
        """
        fct = []  
        b, e = 2, 0  
        while b * b <= n:
            while n % b == 0:
                n = n // b
                e = e + 1
            if e > 0:
                fct.append((b, e))
            b, e = b + 1, 0
        if n > 1:
            fct.append((n, 1))
        return fct
    def combinations_count(n, r):   
        """Return the number of selecting r pieces of items from n kinds of items.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        
        if n < 0 or r < 0:
            raise Exception('combinations_count(n, r) not defined when n or r is negative')
        if n - r < r: r = n - r
        if r < 0: return 0
        if r == 0: return 1
        if r == 1: return n
        numerator = [n - r + k + 1 for k in range(r)]
        denominator = [k + 1 for k in range(r)]
        for p in range(2,r+1):
            pivot = denominator[p - 1]
            if pivot > 1:
                offset = (n - r) % p
                for k in range(p-1,r,p):
                    numerator[k - offset] /= pivot
                    denominator[k] /= pivot
        result = 1
        for k in range(r):
            if numerator[k] > 1:
                result *= int(numerator[k])
        return result
    def combinations_with_replacement_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items allowing individual elements to be repeated more than once.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        if n < 0 or r < 0:
            raise Exception('combinations_with_replacement_count(n, r) not defined when n or r is negative')
        elif n == 0:
            return 1
        else:
            return combinations_count(n + r - 1, r)
    from bisect import bisect_left, bisect_right
    from collections import deque, Counter, defaultdict 
    from heapq import heapify, heappop, heappush, heappushpop, heapreplace,nlargest,nsmallest 
    from copy import deepcopy, copy 
    import operator
    from operator import itemgetter 
    
    
    from functools import reduce, lru_cache
    def chmin(x, y):
        """change minimum
        if x > y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current minimum value
            y (long): potential minimum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x > y:
            x = y
            return (x, True)
        else:
            return (x, False)
    def chmax(x, y):
        """change maximum
        if x < y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current maximum value
            y (long): potential maximum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x < y:
            x = y
            return (x, True)
        else:
            return (x, False)

    from fractions import gcd 
    def gcds(numbers):
        return reduce(gcd, numbers)
    def lcm(x, y):
        return (x * y) // gcd(x, y)
    def lcms(numbers):
        return reduce(lcm, numbers, 1)
    def make_divisors(n, reversed=False):
        """create list of divisors
        
        Args:
            number (int): number from which list of divisors is created
            reversed (bool, optional): ascending order if False. Defaults to False.
        
        Returns:
            list: list of divisors
        """
        divisors = set()
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                divisors.add(i)
                divisors.add(n//i)
        return sorted(list(divisors),reverse=reversed)
    
    
    
    INF = 10 ** 18
    MOD = 10 ** 9 + 7
    AtoZ = list('abcdefghijklmnopqrsruvwxyz')
    modpow = lambda a, n, p = MOD: pow(a, n, p) 
    def modinv(a, p = MOD):
        
        
        return modpow(a, p-2, p)
    def modinv_list(n, p = MOD):
        if n <= 1:
            return [0,1][:n+1]
        else:
            inv_t = [0,1]
            for i in range(2, n+1):
                inv_t += [inv_t[p % i] * (p - int(p / i)) % p]
            return inv_t
    def modfactorial_list(n, p = MOD):
        if n == 0:
            return [1]
        else:
            l = [0] * (n+1)
            tmp = 1
            for i in range(1, n+1):
                tmp = tmp * i % p
                l[i] = tmp
            return l
    def modcomb(n, k, fac_list = [], p = MOD):
        
        
        from math import factorial
        if n < 0 or k < 0 or n < k: return 0
        if n == 0 or k == 0: return 1
        if len(fac_list) <= n:
            a = factorial(n) % p
            b = factorial(k) % p
            c = factorial(n-k) % p
        else:
            a = fac_list[n]
            b = fac_list[k]
            c = fac_list[n-k]
        return (a * modpow(b, p-2, p) * modpow(c, p-2, p)) % p
    def modadd(a, b, p = MOD):
        return (a + b) % MOD
    def modsub(a, b, p = MOD):
        return (a - b) % p
    def modmul(a, b, p = MOD):
        return ((a % p) * (b % p)) % p
    def moddiv(a, b, p = MOD):
        return modmul(a, modpow(b, p-2, p))

    class UnionFindTree:
        """union find tree class
        TODO: fix this description...
        how to use (example):
        >>  uf = UnionFindTree(N) 
        >>  if uf.find_root(a) == uf.find_root(b):
        >>      do something
        >>  else:
        >>      do something
        >>      uf.unite(a, b)
        """
        def __init__(self, N):
            self.root = [-1] * (N+1)
            self.rank   = [0]  * (N+1)
            self.connected_num = [1] * (N+1)
    
        def find_root(self,x):
            root = self.root
            while root[x] != -1:
                x = root[x]
            return x
    
        def unite(self,x,y):
            root = self.root
            rank = self.rank
            connected_num = self.connected_num
            find_root = self.find_root
    
            rx = find_root(x)
            ry = find_root(y)
            if rx != ry:
                if rank[rx] < rank[ry]:
                    root[rx] = ry
                    rx,ry = ry,rx
                else:
                    if rank[rx] == rank[ry]:
                        rank[rx] += 1
                    root[ry] = rx       
                connected_num[rx] += connected_num[ry]

    
    
    
    
    

    def BellmanFord(N, M, ABC, vertex_start, vertex_end, value_if_inf = -1, find_shortest = False):
        """to calculate furthest or shortest length between vertex_start and vertex_end using BellmanFord algorithm
        
        Args:
            N (int): number of vertices
            M (int): number of edges
            ABC (list): [(ai, bi, ci) for _ in range(N)] where i-th edge is directed from vertex ai to vertex bi and the length is ci 
            vertex_start (int): start vertex. usually use 0.
            vertex_end (int): end vertex. usually use N-1.
            value_if_inf (int or string as you like, optional): value you want when the furthest (or shortest) distance is infinite (or -infinite). Defaults to -1.
            find_shortest (bool, optional): choose False to find furthest path. Defaults to False.
        
        Returns:
            int or string: normally int (but can be str if you set value_if_inf to str)
            
        Example:
                N, M, P = R()
                ABC = [R() for _ in range(M)]
                ABC = [(a-1, b-1, c-P) for a, b, c in ABC]
                print(BellmanFord(N, M, ABC, 0, N-1, value_if_inf = 'inf'))

        """

        def make_reachable_list(N, M, ABC, vertex_start, vertex_end):
            reachable_to_direct = defaultdict(list)
            reachable_from_direct = defaultdict(list)
            reachable_from_start = [False] * N
            reachable_to_end = [False] * N
            reachable_from_start[vertex_start] = True
            reachable_to_end[vertex_end] = True
            reachable_from_both_sides = [False] * N
            dfs_from_start = []
            dfs_to_end = []
            for a, b, c in ABC:
                reachable_to_direct[a].append(b)
                reachable_from_direct[b].append(a)
                if a == vertex_start:
                    dfs_from_start.append(b)
                    reachable_from_start[b] = True
                if b == vertex_end:
                    dfs_to_end.append(a)
                    reachable_to_end[a] = True
            while dfs_from_start:
                v = dfs_from_start.pop()
                for i in reachable_to_direct[v]:
                    if not reachable_from_start[i]:
                        reachable_from_start[i] = True
                        dfs_from_start.append(i)
            while dfs_to_end:
                v = dfs_to_end.pop()
                for i in reachable_from_direct[v]:
                    if not reachable_to_end[i]:
                        reachable_to_end[i] = True
                        dfs_to_end.append(i)
            for i in range(N):
                reachable_from_both_sides[i] = reachable_from_start[i] and reachable_to_end[i]
            return reachable_from_both_sides
        
        reachable_from_both_sides = make_reachable_list(N, M, ABC, vertex_start, vertex_end)
        
        if find_shortest:
            dist = [INF for i in range(N)]
        else:
            dist = [-INF for i in range(N)]
        
        dist[vertex_start] = 0
        for i in range(N):
            updated = False
            for a, b, c in ABC:
                if not reachable_from_both_sides[a]:
                    continue
                elif find_shortest:
                    update_condition = dist[a] + c < dist[b]
                else:
                    update_condition = dist[a] + c > dist[b]
                if dist[a] != INF and update_condition:
                    dist[b] = dist[a] + c
                    updated = True
                    if i == N-1:
                        return value_if_inf
            if not updated:
                break
        return dist[vertex_end]

    """ initialize variables and set inputs
    
        
        
            
            
    
        
        
        
        
        
        
        
    
        
        
        
        
    
        
        
    """

    
    r = lambda: sys.stdin.readline().strip()
    r_int = lambda: int(r())
    r_float = lambda: float(r())
    R = lambda: list(map(int, r().split()))
    R_str = lambda: r().split()
    R_map = lambda: map(int, r().split())
    R_float = lambda: list(map(float, r().split()))
    R_tuple = lambda: tuple(map(int, r().split()))

    """ how to treat input
    
    
    
    
    
    
    
    """

    
    if sample_file:
        sys.stdin = open(sample_file)
        
    
    
    
    import itertools
    N, M, Q = R()
    ABCD = [R() for i in range(Q)]
    ans = 0
    for i in set(itertools.combinations_with_replacement(range(1, M+1), N)):
        tmp = 0
        for a, b, c, d in ABCD:
            if i[b-1] - i[a-1] == c:
                tmp += d
        ans = max(tmp, ans)
    print(ans)
    
    
    
    

    """memo: how to use defaultdict of list
    
    Dic = defaultdict(list)
    
    Dic[x].append(y)
    
    for k, v in Dic.items():
    """
    
    """memo: how to solve binary problems
    
    >>> a = 5
    >>> bin_str_a = format(a, '
    >>> print(bin_str_a)
    0b0101 
    """
    
    """memo: how to solve the problem
    creating simple test/answer
    greed
    simple dp
    graph
    """

if __name__ == '__main__':
    main()

Solution (Python):
import sys
input = sys.stdin.readline
N, M, Q = map(int, input().split())
a = []
b = []
c = []
d = []
for _ in range(Q):
    w,x,y,z = map(int, input().split())
    w -= 1
    x -= 1
    a.append(w)
    b.append(x)
    c.append(y)
    d.append(z)
def dfs(A_, k):
    if k == N-1:
        res = 0
        for i in range(Q):
            if A_[b[i]] - A_[a[i]] == c[i]:
                res += d[i]
        return res
    x = A_[k]
    res = 0
    for i in range(x, M+1):
        A_[k+1] = i
        res = max(res, dfs(A_, k+1))
    return res

ans = 0
A = [1]*N
for i in range(1, M+1):
    A[0] = i
    ans = max(ans, dfs(A, 0))
print(ans)

Solution (Python):
import math
import itertools
n,m,q=map(int,input().split())
A=[0]*q
B=[0]*q
C=[0]*q
D=[0]*q
for i in range(q):
  A[i],B[i],C[i],D[i]=map(int,input().split())
l = [i for i in range(1,m+1)]
ans=0
for v in itertools.combinations_with_replacement(l,n):
  a=0
  for i in range(q):
    if v[B[i]-1]-v[A[i]-1]==C[i]:
      a=a+D[i]
  if a>ans:
    ans=a
print(ans)

Solution (Python):
import sys, itertools
input = lambda: sys.stdin.readline().rstrip() 
sys.setrecursionlimit(10**7)
INF = 10**20
def I(): return int(input())
def F(): return float(input())
def S(): return input()
def LI(): return [int(x) for x in input().split()]
def LI_(): return [int(x)-1 for x in input().split()]
def LF(): return [float(x) for x in input().split()]
def LS(): return input().split()

def resolve():
    N, M, Q = LI()
    abcd = [LI() for _ in range(Q)]

    ans = 0
    for i in itertools.combinations_with_replacement(range(1, M+1), N):
        
        score = 0
        for j in abcd:
            a = j[0]-1
            b = j[1]-1
            c = j[2]
            d = j[3]
            if i[b]-i[a]==c:
                score += d
        ans = max(score, ans)

    print(ans)


if __name__ == '__main__':
    resolve()

Solution (Python):
from itertools import combinations_with_replacement
N, M, Q = map(int, input().split())
list1 = []
for i in range(Q):
    l = list(map(int, input().split()))
    list1.append(l)
ans = 0
list2 = [i for i in range(1, M+1)]
for l in combinations_with_replacement(list2, N):
    tmp = 0
    for i in range(Q):
        if l[list1[i][1]-1]-l[list1[i][0]-1]==list1[i][2]:
            tmp += list1[i][3]
    if tmp >= ans:
        ans = tmp
print(ans)

Solution (Python):
import sys
from itertools import permutations, combinations, combinations_with_replacement
int1 = lambda x: int(x) - 1
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(500000)

N, M, Q = map(int, readline().split())
abcd = [list(map(int, readline().split())) for _ in range(Q)]
l = [i for i in range(1, M + 1)]

ans = 0
for v in combinations_with_replacement(l, N):
    acc = 0
    for a, b, c, d in abcd:
        if v[b - 1] - v[a - 1] == c:
            acc += d
    ans = max(ans, acc)

print(ans)

Solution (Python):















mod = int(1e9+7)
INF = 1<<29
lINF = 1<<35

def readInt():
    return list(map(int,input().split()))

def func():
    global a,q,ans
    res = 0
    for x in q:
        if a[x[1]-1]-a[x[0]-1]==x[2]:
            res += x[3]
    ans = max(ans,res)
    return

def dfs(pos):
    global a,n,m
    if pos==n:
        return func()
    for i in range(max(1,a[pos-1]),m+1):
        a[pos] = i
        dfs(pos+1)

def main():
    global a,n,m,Q,q,ans
    n,m,Q = readInt()
    q = []
    for i in range(Q):
        q.append(readInt())
    ans = 0
    a = [0 for i in range(n)]
    dfs(0)
    print(ans)
    return

if __name__=='__main__':
    main()

Solution (Python):
from collections import deque, Counter, defaultdict
from itertools import chain, combinations
import json

import bisect
import sys
import math
import bisect
from functools import lru_cache
import itertools

sys.setrecursionlimit(10 ** 8)

M = 10 ** 9 + 7
INF = 10 ** 17


def f(start, end, n):
    if n == 1:
        for i in range(start, end + 1):
            yield [i]
        return
    for i in range(start, end + 1):
        for nn in f(i, end, n - 1):
            yield [i] + nn


def main():
    
    N, M, Q = [int(a) for a in input().split()]
    abcd = [
        [int(a) for a in input().split()]
        for _ in range(Q)
    ]


    res = 0
    for v in f(1, M, N):

        total = 0
        for a, b, c, d in abcd:
            if v[b - 1] - v[a - 1] == c:
                total += d

        res = max(res, total)
    print(res)


if __name__ == "__main__":
    main()

Solution (Python):
n, m, q = map(int, input().split())
queries = []
for _ in range(q):
    a, b, c, d = map(int, input().split())
    queries.append([a-1, b-1, c, d])

patterns = []

todo = ['0']
while todo:
    num = todo.pop()
    if len(num) == n:
        patterns.append(num)
        continue

    last = int(num[-1])
    for new_num in range(last, m):
        new = num + str(new_num)
        todo.append(new)

candidates = []
for pattern in patterns:
    res = 0
    for a, b, c, d in queries:
        if int(pattern[b]) - int(pattern[a]) == c:
            res += d

    candidates.append(res)

print(max(candidates))

Solution (Python):
import sys
sys.setrecursionlimit(10**9)

N, M, Q = list(map(int, input().split()))
a, b, c, d = [0] * Q, [0] * Q, [0] * Q, [0] * Q
for i in range(Q):
    a[i], b[i], c[i], d[i] = list(map(int, input().split()))

def saiki(i, last, list):
    if(i == N):
        sum = 0
        for q in range(Q):
            if(list[b[q]-1] - list[a[q]-1] == c[q]):
                sum += d[q]
        return sum
    res = 0
    for x in range(last, M+1):
        list.append(x)
        res = max(res, saiki(i+1, x, list))
        list.pop(-1)
    return res

all = saiki(0, 1, [])
print(all)

Solution (Python):
import sys
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
read = sys.stdin.buffer.read
sys.setrecursionlimit(10 ** 7)

N, M, Q = map(int, readline().split())
q_kumi = []
for _ in range(Q):
    q_kumi.append(list(map(int, readline().split())))

import itertools
AL = itertools.combinations_with_replacement(range(1, M+1), N)

ans = 0
for A in AL:
    tmp_ans = 0
    for kumi in q_kumi:
        if A[kumi[1]-1] - A[kumi[0]-1] == kumi[2]:
            tmp_ans += kumi[3]
    ans = max(ans, tmp_ans)


print(ans)

Solution (Python):
from itertools import combinations_with_replacement
def main():
    n, m, q = map(int, input().split())
    query = []
    for _ in range(q):
        a, b, c, d = map(int, input().split())
        query.append([a, b, c, d])
    
    ele = [i for i in range(1, m+1)]
    
    ans = -1
    for comb in combinations_with_replacement(ele, n):
        comb = sorted(comb)
        tmp = 0
        for qu in query:
            if comb[qu[1]-1] - comb[qu[0]-1] == qu[2]:
                tmp += qu[3]
            else:
                continue
        if tmp > ans:
            ans = tmp
    print(ans)
    
main()

Solution (Python):
import itertools

N, M, Q = map(int, input().split())

L = []
for _ in range(Q):
    L.append(list(map(int, input().split())))

C = itertools.combinations_with_replacement(range(1, M + 1), N)
ans = 0

for c in C:
    tmp = 0
    for l in L:
        if c[l[1] - 1] - c[l[0] - 1] == l[2]:
           tmp += l[3]
    ans = max(ans, tmp)
print(ans)

Solution (Python):
import itertools

n,m,q = list(map(int, input().split()))
lst = [None for i in range(q)]
for i in range(q):
    a,b,c,d = list(map(int, input().split()))
    lst[i] = (a,b,c,d)

numlst = [i+1 for i in range(m)]
comb = list(itertools.combinations_with_replacement(numlst,n))

ans = 0
for i in comb:
    
    koho = 0
    for Q in range(q):
        
        
        if i[lst[Q][1]-1]-i[lst[Q][0]-1]==lst[Q][2]:
            koho+=lst[Q][3]
            
    
    ans = max(ans, koho)

print(ans)

Solution (Python):



INF = 2**62-1

def read_int():
    return int(input())


def read_int_n():
    return list(map(int, input().split()))


def read_float():
    return float(input())


def read_float_n():
    return list(map(float, input().split()))


def read_str():
    return input().strip()


def read_str_n():
    return list(map(str, input().split()))


def error_print(*args):
    print(*args, file=sys.stderr)

def slv(N, M, Q, ABCD):

    def dfs(a, n):
        r = 0
        if n == N:
            t = 0
            for abcd in ABCD:
                A, B, C, D = abcd
                if a[B] - a[A] == C:
                    t += D
            return t
        b = a[-1]
        for c in range(b, M+1):
            a.append(c)
            r = max(r, dfs(a, n+1))
            a.pop()
        return r
    return dfs([1], 0)


def main():
    N, M, Q = read_int_n()
    ABCD = [read_int_n() for _ in range(Q)]
    print(slv(N, M, Q, ABCD))


if __name__ == '__main__':
    main()

Solution (Python):
from itertools import combinations_with_replacement
N, M, Q = map(int, input().split())
L = list(range(1, M+1))

D = [list(map(int, input().split())) for _ in range(Q)]
ans = []

for p in combinations_with_replacement(L, N):
    tmp = 0
    for a, b, c, d in D:
        if p[b-1]-p[a-1] == c:
            tmp += d
    ans.append(tmp)

print(max(ans))

Solution (Python):
from itertools import combinations
N, M, Q = map(int, input().split())
qs = []
for _ in range(Q):
    qs.append(tuple(map(int, input().split())))

ans = 0
for cs in combinations(range(N+M-1), M-1):
    cs = set(cs)
    arr = []
    tmp = 0
    i = 0
    for k in range(N+M-1):
        if k in cs:
            tmp += 1
        else:
            arr.append(tmp)
            i += 1
        if i >= N:
            break
    score = 0
    for a, b, c, d in qs:
        if arr[b-1] - arr[a-1] == c:
            score += d
    ans = ans if ans > score else score
print(ans)

Solution (Python):
from itertools import combinations_with_replacement
N, M, Q = [int(x) for x in input().split()]
lst = [list(map(int, input().split())) for _ in range(Q)]
ans = 0
for seq in combinations_with_replacement(range(1, M+1), N):
    tmp = 0
    for a, b, c, d in lst:
        if (seq[b-1] - seq[a-1] == c):
            tmp += d
    ans = max(ans, tmp)
print(ans)

Solution (Python):
import os
from functools import reduce
from operator import mul

import itertools
import sys

if os.getenv("LOCAL"):
    sys.stdin = open("_in.txt", "r")

sys.setrecursionlimit(10 ** 9)
INF = float("inf")
IINF = 10 ** 18
MOD = 10 ** 9 + 7





def ncr(n, r, mod=None):
    """
    組み合わせの数 nCr
    :param int n:
    :param int r:
    :param int mod: 3 以上の素数であること
    :rtype: int
    """
    if n < r:
        return 0

    
    r = min(n - r, r)
    if r == 0:
        return 1
    if mod:
        return reduce(mul, range(n, n - r, -1)) * mod_inv(reduce(mul, range(r, 0, -1)), mod) % mod
    else:
        
        
        return reduce(mul, range(n, n - r, -1)) // reduce(mul, range(r, 0, -1))


def nhr(n, r, mod=None):
    """
    重複組み合わせの総数 nHr
    :param int n:
    :param int r:
    :param int mod:
    """
    return ncr(n + r - 1, r, mod)


def cumsum(it):
    """
    累積和
    :param collections.Iterable it:
    """
    cs = 0
    ret = []
    for v in it:
        cs += v
        ret.append(cs)
    return ret



N, M, Q = list(map(int, sys.stdin.buffer.readline().split()))
ABCD = [list(map(int, sys.stdin.buffer.readline().split())) for _ in range(Q)]

ans = 0
for r in range(M):
    for idx in itertools.combinations_with_replacement(range(1, N + 1), r=r):
        a = [0] * (N + 10)
        a[1] = 1
        for i in idx:
            a[i] += 1
        cum = cumsum(a)
        
        pt = 0
        for a, b, c, d in ABCD:
            if cum[b] - cum[a] == c:
                pt += d
        ans = max(ans, pt)
print(ans)

Solution (Python):
N, M, Q = map(int, input().split())
L = []
for i in range(Q):
    ai, bi, ci, di = map(int, input().split())
    ai -= 1
    bi -= 1
    L.append((ai, bi, ci, di))


def dfs(A):
    if len(A) == N:
        r = 0
        for Li in L:
            if A[Li[1]] - A[Li[0]] == Li[2]:
                r += Li[3]
        return r
    r = 0
    for i in range(A[-1], M + 1):
        r = max(r, dfs(A + [i]))
    return r


print(dfs([1]))

Solution (Python):
n, m, q = map(int, input().split())
X = [list(map(int, input().split())) for _ in range(q)]

ans = 0

from itertools import combinations_with_replacement

for _x in combinations_with_replacement(range(1,m+1), n):
    _ans = 0
    for (a, b, c, d) in X:
        if _x[b-1] - _x[a-1] == c:
            _ans += d
    ans = max(ans, _ans)

print(ans)

Solution (Python):
import itertools

N, M, Q = map(int, input().split())
q_list = []
for i in range(Q):
    q = list(map(int, input().split()))
    q_list.append(q)
l = []
for i in range(1,M+1):
    l.append(i)
A_list = list(itertools.combinations_with_replacement(l, N))
ans = 0

for A in A_list:
    s = 0
    for q in q_list:
        if A[q[1]-1] - A[q[0]-1] == q[2]:
            s += q[3]
    if s > ans:
        ans = s

print(ans)

Solution (Python):

import sys
from itertools import combinations
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
input=lambda: sys.stdin.readline().rstrip()
YesNo=lambda b: bool([print('Yes')] if b else print('No'))
YESNO=lambda b: bool([print('YES')] if b else print('NO'))
int1=lambda x:int(x)-1

def main():
    N,M,Q=map(int,input().split())
    a,b,c,d=[0]*Q,[0]*Q,[0]*Q,[0]*Q
    for i in range(Q):
        a[i],b[i],c[i],d[i]=map(int,input().split())
        a[i]-=1
        b[i]-=1
    ans=0
    tmp_l=[[i] for i in range(1,M+1)]
    next=[]
    for _ in range(N-1):
        for l in tmp_l:
            for i in range(l[-1],M+1):
                next.append(l+[i])
        tmp_l=next[:]
        next=[]
    for A in tmp_l:
        tmp=0
        for i in range(Q):
            if A[b[i]]-A[a[i]]==c[i]:
                tmp+=d[i]
        ans=max(ans,tmp)
    print(ans)

if __name__ == '__main__':
    main()

Solution (Python):
import math
import sys
from bisect import bisect_left, bisect_right
from collections import Counter, defaultdict, deque
from functools import lru_cache, reduce
from heapq import heapify, heappop, heappush
from itertools import chain, combinations, permutations, product
from typing import List, Dict



sys.setrecursionlimit(10**5 + 1)
input = sys.stdin.readline
write = sys.stdout.write


def read_item(cls=int):
    return cls(input())


def read_n_item(cls=int) -> list:
    return [cls(s) for s in input().split()]


def list2d(row, col, init_val=0) -> List[list]:
    return [[init_val] * col for _ in range(row)]


MOD = 10**9 + 7



N, M, Q = read_n_item()
items = []
for _ in range(Q):
    items.append(read_n_item())


def calc(cur, items):
    ans = 0
    for a, b, c, d in items:
        if cur[b-1] - cur[a-1] == c:
            ans += d
    return ans


def dfs(cur, pre):
    
    if len(cur) == N:
        return calc(cur, items)
    ans = 0
    for i in range(pre, M+1):
        cur.append(i)
        ans = max(ans, dfs(cur, i))
        cur.pop()
    return ans


print(dfs([], 1))

Solution (Python):
from sys import stdin
from sys import setrecursionlimit
from itertools import combinations_with_replacement


n,m,q = map(int,stdin.readline().rstrip().split())

abcd = [list(map(int,stdin.readline().rstrip().split())) for _ in range(q)]
abcd.sort()

maxes = 0

kazu = [i for i in range(1,m+1)]

li = list(combinations_with_replacement(kazu,n))

for i in li:
    i = list(i)
    ma = 0
    for j in abcd:
        a,b,c,d = j
        a -= 1;b -= 1
        if i[b]-i[a] == c:
            ma += d
    maxes = max(ma,maxes)
print(maxes)

Solution (Python):
N, M, Q = map(int, input().split())
data = []
for _ in range(Q):
	data.append(tuple(map(int, input().split())))

max_total = 0
def check(items, l):
	global max_total
	if l == N + 1:
		total = 0
		for a, b, c, d in data:
			if items[b] - items[a] == c:
				total += d
		if max_total < total:
			max_total = total
	else:
		for i in range(items[l - 1], M + 1):
			items[l] = i
			check(items, l + 1)

items = [None] * (N + 1)
items[0] = 1
check(items, 1)

print(max_total)

Solution (Python):
n,m,q=map(int, input().split())
abcd=[list(map(int, input().split())) for i in range(q)]
from itertools import combinations_with_replacement
data=list(range(1,m+1))
prep=combinations_with_replacement(data, n)
ans=0
for p in prep:
    tmp=0
    p=sorted(list(p))
    for i in range(q):
        if p[abcd[i][1]-1]-p[abcd[i][0]-1]==abcd[i][2]:
            tmp+=abcd[i][3]
    ans=max(ans,tmp)
print(ans)

Solution (Python):
import itertools
n,m,q=map(int,input().split())
l=[list(map(int,input().split())) for i in range(q)]
x=0
for v in itertools.combinations_with_replacement(range(1,m+1),n):
  t=list(v)
  p=0
  for i in l:
    p+=(i[3]*(t[i[1]-1]-t[i[0]-1]==i[2]))
  x=max(x,p)
print(x)

Solution (Python):
n,m,q = map(int, input().split())
abcd = [list(map(int, input().split())) for _ in range(q)]


def sol(list):
    res = 0
    for i in range(q):
        if list[abcd[i][1]-1] - list[abcd[i][0]-1] == abcd[i][2]:
            res += abcd[i][3]
    return res


def dfs(i, la):
    if i == n-1:
        return sol(la)
    else:
        last = 1
        if i >= 0:
            last = la[-1]
        res = 0
        for j in range(last, m+1):
            res = max(res, dfs(i+1, la+[j]))
        return res

print(dfs(-1,[]))

Solution (Python):
import itertools

n, m, q = map(int, input().split())
query = []
for i in range(q):
    query.append(list(map(int, input().split())))

choices = list(itertools.combinations_with_replacement([i for i in range(1, m+1)], n))
ans = -1
for choice in choices:
    score = 0
    for q in query:
        if choice[q[1]-1] - choice[q[0]-1] == q[2]:
            score += q[3]
    ans = max(ans, score)
print(ans)