Buggy python submission (verdict: Time Limit Exceeded):
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())

  
from copy import deepcopy

ans_list=[]
def dfs(x,M,N,ans):
  if len(ans)<=N-1:
    for j in range(x,M+1):
      tmp=deepcopy(ans)
      tmp.append(j)
      if len(tmp)==N:
        ans_list.append(tmp)
      else:
        for k in range(j,M+1):
          dfs(k,M,N,tmp)
    
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Fixed submission:
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Buggy python submission (verdict: Time Limit Exceeded):
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())

  
from copy import deepcopy

ans_list=[]
def dfs(x,M,N,ans):
  if len(ans)<=N-1:
    for j in range(x,M+1):
      tmp=deepcopy(ans)
      tmp.append(j)
      if len(tmp)==N:
        ans_list.append(tmp)
      else:
        for k in range(j,M+1):
          dfs(k,M,N,tmp)
    
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Fixed submission:
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Buggy python submission (verdict: Time Limit Exceeded):
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      if ans not in ans_list:
        ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Fixed submission:
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations_with_replacement

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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    for i in range(x,M+1):
      tmp=deepcopy(ans)
      dfs(i,M,N,tmp)
  else:    
    if ans not in ans_list:
      ans_list.append(ans)
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Fixed submission:
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Buggy python submission (verdict: Time Limit Exceeded):
from itertools import combinations_with_replacement

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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    for i in range(x,M+1):
      tmp=deepcopy(ans)
      dfs(i,M,N,tmp)
  else:    
    if ans not in ans_list:
      ans_list.append(ans)
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)

Fixed submission:
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())

ans_list=[]  
from copy import deepcopy
def dfs(x,M,N,ans):
  if len(ans)<=N:
    ans.append(x)
    if len(ans)==N:
      ans_list.append(ans)
    else:
      for i in range(x,M+1):
        tmp=deepcopy(ans)
        dfs(i,M,N,tmp)   
      
q=dfs(1,M,N,[])

f=0
for A in ans_list:
  cnt=0
  for i in range(Q):
    if A[b[i]-1]-A[a[i]-1]==c[i]:
      cnt += d[i]
  f=max(f,cnt)
  
print(f)