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

N = int(input())
A = list(map(int, input().split()))

def honya(n, L):
  k = 0
  E = len(L)
  for i in range(n - 1, -1, -1):
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[k], L[j] = L[j], L[k]
        break
    else:
      continue
    k += 1
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[j] ^= L[k - 1]
  return L

def nasu(n):
  return math.ceil(math.log(n + 1, 2))

A.sort(reverse = True)
M = nasu(A[0])
P = [1]
for i in range(M):
  P.append(P[-1] * 2)

D = [0] * M
for i in range(N):
  t = A[i]
  for j in range(M):
    if t & 1:
      D[j] += 1
    t >>= 1

ans = 0
for i in range(M - 1, -1, -1):
  if D[i] % 2 == 1:
    ans += P[i]
    for j in range(N):
      A[j] &= ~(1 << i)

L = honya(M, A)
t = 0
for i in range(N):
  if L[i] == 0: break
  if (t & (1 << (nasu(L[i]) - 1))) == 0:
    t ^= L[i]

for i in  range(M - 1, -1, -1):
  if (t >> i) & 1:
    ans += P[i] * 2
    
print(ans)


Fixed submission:
import math

N = int(input())
A = list(map(int, input().split()))

def honya(n, L):
  k = 0
  E = len(L)
  for i in range(n - 1, -1, -1):
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[k], L[j] = L[j], L[k]
        break
    else:
      continue
    k += 1
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[j] ^= L[k - 1]
  return L

def nasu(n):
  return math.ceil(math.log(n + 1, 2))

A.sort(reverse = True)
M = nasu(A[0])
P = [1]
for i in range(M):
  P.append(P[-1] * 2)

D = [0] * M
for i in range(N):
  t = A[i]
  for j in range(M):
    if t & 1:
      D[j] += 1
    t >>= 1

ans = 0
for i in range(M - 1, -1, -1):
  if D[i] % 2 == 1:
    ans += P[i]
    for j in range(N):
      A[j] &= ~(1 << i)

L = honya(M, A)
t = 0
for i in range(N):
  if L[i] == 0: break
  if (t & (1 << (nasu(L[i]) - 1))) == 0:
    t ^= L[i]

for i in  range(M - 1, -1, -1):
  if (t >> i) & 1:
    ans += P[i] * 2
    
print(ans)

Buggy python submission (verdict: Runtime Error):
import math

N = int(input())
A = list(map(int, input().split()))

X = []
Y = []

def nasu(n):
  return math.ceil(math.log(n, 2))

def honya(n, L, X, Y):
  if len(L) >= 2:
    X.append(L[0])
    Y.append(L[1:])
    return True
  cnt = 0
  for i in Y:
    if (i >> (n - 1)) & 1:
      cnt += 1
  if cnt % 2 == 1:
    X.append(L)
    return True


A.sort(reverse = True)

M = nasu(A[0])

D = [0] * M
for i in range(N):
  t = A[i]
  for j in range(M):
    if t & 1:
      D[j] += 1
    t >>= 1

cnt = 0
ans = 0
X = []
Y = []
for i in range(M, 0, -1):
  L = []
  while nasu(A[cnt]) == i:
    L.append(A[cnt])
    cnt += 1
    if cnt == N:
      break
  else:
    if D[i - 1] % 2 == 1:
      X.append(L)
      ans += pow(2, i - 1)
    else:
      if honya(i, L, X, Y):
        ans += pow(2, M - 1) * 2
    continue
  break
print(ans)

Fixed submission:
import math

N = int(input())
A = list(map(int, input().split()))

def honya(n, L):
  k = 0
  E = len(L)
  for i in range(n - 1, -1, -1):
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[k], L[j] = L[j], L[k]
        break
    else:
      continue
    k += 1
    for j in range(k, E):
      if (L[j] >> i) & 1:
        L[j] ^= L[k - 1]
  return L

def nasu(n):
  return math.ceil(math.log(n + 1, 2))

A.sort(reverse = True)
M = nasu(A[0])
P = [1]
for i in range(M):
  P.append(P[-1] * 2)

D = [0] * M
for i in range(N):
  t = A[i]
  for j in range(M):
    if t & 1:
      D[j] += 1
    t >>= 1

ans = 0
for i in range(M - 1, -1, -1):
  if D[i] % 2 == 1:
    ans += P[i]
    for j in range(N):
      A[j] &= ~(1 << i)

L = honya(M, A)
t = 0
for i in range(N):
  if L[i] == 0: break
  if (t & (1 << (nasu(L[i]) - 1))) == 0:
    t ^= L[i]

for i in  range(M - 1, -1, -1):
  if (t >> i) & 1:
    ans += P[i] * 2
    
print(ans)