Buggy python submission (verdict: Runtime Error):
import numpy as np
N = int(input())
A = np.array(list(map(int, input().split())))
a = np.bitwise_xor.reduce(A)
A^=a
for k in range(60, -1, -1):
    bit = 1<<k
    one = (A&bit != 0)
    i = np.where(one & (A < (1<<(k+1))))[0]
    if len(i) == 0:
        continue
    i = i[0]
    x = A[i]
    A[one]^=x
    A[i] = x
b = np.bitwise_xor.reduce(A)
a^=b
print(a+b)

Fixed submission:
import numpy as np
N = int(input())
A = np.array(list(map(int, input().split())), dtype = np.int64)
a = np.bitwise_xor.reduce(A)
for i in range(60):
    bit = 1<<i
    if bit & a:
        A^=(A&bit)
for k in range(60, -1, -1):
    bit = 1<<k
    one = (A&bit != 0)
    i = np.where(one & (A < (1<<(k+1))))[0]
    if len(i) == 0:
        continue
    i = i[0]
    x = A[i]
    A[one]^=x
    A[i] = x
b = np.bitwise_xor.reduce(A)
a^=b
print(a+b)

Buggy python submission (verdict: Runtime Error):
import numpy as np
from numpy.fft import fft, ifft
from bisect import bisect_left
import sys
Max = 10**6
N, M = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = np.zeros(Max+1)
D = np.zeros(Max+1)
for a in A:
    C[a] +=1
for b in B:
    D[b]+=1
L = 2**8
res = ifft(fft(C, L)*fft(D, L))
res = np.where(res>1.5)
if res[0].size == 0:
    print(-1)
    sys.exit()
res = res[0][-1]
B.sort()
ans  = []
for i, a in enumerate(A):
    j = bisect_left(B, res-a)
    b = B[j]
    if b == res-a:
        ans.append(i)
        ans.append(j)
    if len(ans) == 4:
        break
if len(ans) < 4:
    print(liahbcon)
print(*ans)    
    


Fixed submission:
import numpy as np
N = int(input())
A = np.array(list(map(int, input().split())), dtype = np.int64)
a = np.bitwise_xor.reduce(A)
for i in range(60):
    bit = 1<<i
    if bit & a:
        A^=(A&bit)
for k in range(60, -1, -1):
    bit = 1<<k
    one = (A&bit != 0)
    i = np.where(one & (A < (1<<(k+1))))[0]
    if len(i) == 0:
        continue
    i = i[0]
    x = A[i]
    A[one]^=x
    A[i] = x
b = np.bitwise_xor.reduce(A)
a^=b
print(a+b)

Buggy python submission (verdict: Runtime Error):
import numpy as np
from numpy.fft import rfft, irfft
from bisect import bisect_left
import sys
Max = 10**6
N, M = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = np.zeros(Max+1)
D = np.zeros(Max+1)
for a in A:
    C[a] +=1
for b in B:
    D[b]+=1
L = 2**8
res = irfft(rfft(C, L)*rfft(D, L))
res = np.where(res>1.4)
if res[0].size == 0:
    print(ahfkgashg)
    sys.exit()
res = res[0][-1]
B.sort()
ans  = []
for i, a in enumerate(A):
    j = bisect_left(B, res-a)
    b = B[j]
    if b == res-a:
        ans.append(i)
        ans.append(j)
    if len(ans) == 4:
        break
if len(ans) < 4:
    print(liahbcon)
print(*ans)    
    


Fixed submission:
import numpy as np
N = int(input())
A = np.array(list(map(int, input().split())), dtype = np.int64)
a = np.bitwise_xor.reduce(A)
for i in range(60):
    bit = 1<<i
    if bit & a:
        A^=(A&bit)
for k in range(60, -1, -1):
    bit = 1<<k
    one = (A&bit != 0)
    i = np.where(one & (A < (1<<(k+1))))[0]
    if len(i) == 0:
        continue
    i = i[0]
    x = A[i]
    A[one]^=x
    A[i] = x
b = np.bitwise_xor.reduce(A)
a^=b
print(a+b)