Buggy python submission (verdict: Runtime Error):
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

for i in range(N-1):
    if a_list[i] + a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

ans = sum(a_list)

min_list = []
for i in range(N):
    if a_list[i] < 0:
        min_list.append(a_list[i])

if len(min_list) % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)

if len(min_list) % 2 == 1 and len(min_list) !=1 :
    abc.sort()
    min_list = min_list[:-1]
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)
else:
    print(ans)

Fixed submission:
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

counter = 0
min_list = []
for i in range(N):
    if a_list[i] < 0:
        counter += 1
        min_list.append(a_list[i])

if counter % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    ans = sum(a_list)
    print(ans + 2*abc)

if counter % 2 == 1:
    for i in range(N):
        if a_list[i] < 0:
            a_list[i] *= -1
    min_mun = min(a_list)
    ans = sum(a_list) - 2*min_mun
    print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

for i in range(N-1):
    if a_list[i] + a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

ans = sum(a_list)

min_list = []
for i in range(N):
    if a_list[i] < 0:
        min_list.append(a_list[i])

if len(min_list) % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)

if len(min_list) % 2 == 1 and len(min_list) != 1:
    abc.sort()
    min_list = min_list[:-1]
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc) 


Fixed submission:
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

counter = 0
min_list = []
for i in range(N):
    if a_list[i] < 0:
        counter += 1
        min_list.append(a_list[i])

if counter % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    ans = sum(a_list)
    print(ans + 2*abc)

if counter % 2 == 1:
    for i in range(N):
        if a_list[i] < 0:
            a_list[i] *= -1
    min_mun = min(a_list)
    ans = sum(a_list) - 2*min_mun
    print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-2):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

for i in range(N-2):
    if a_list[i] + a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

ans = sum(a_list)

min_list = []
for i in range(N):
    if a_list[i] < 0:
        min_list.append(a_list[i])

if len(min_list) % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)

if len(min_list) % 2 == 1 and len(min_list) !=1 :
    abc.sort()
    min_list = min_list[:-1]
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)

Fixed submission:
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

counter = 0
min_list = []
for i in range(N):
    if a_list[i] < 0:
        counter += 1
        min_list.append(a_list[i])

if counter % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    ans = sum(a_list)
    print(ans + 2*abc)

if counter % 2 == 1:
    for i in range(N):
        if a_list[i] < 0:
            a_list[i] *= -1
    min_mun = min(a_list)
    ans = sum(a_list) - 2*min_mun
    print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-2):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

for i in range(N-2):
    if a_list[i] + a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

ans = sum(a_list)

min_list = []
for i in range(N-1):
    if a_list[i] < 0:
        min_list.append(a_list[i])

if len(min_list) % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc)

if len(min_list) % 2 == 1:
    abc.sort()
    min_list = min_list[:-1]
    abc = sum(min_list)
    abc *= -1
    print(ans + 2*abc) 


Fixed submission:
N = int(input())
a_list = list(map(int, input().split()))

for i in range(N-1):
    if a_list[i] <0 and a_list[i+1] < 0:
       a_list[i] *= -1
       a_list[i+1] *= -1

counter = 0
min_list = []
for i in range(N):
    if a_list[i] < 0:
        counter += 1
        min_list.append(a_list[i])

if counter % 2 == 0:
    abc = sum(min_list)
    abc *= -1
    ans = sum(a_list)
    print(ans + 2*abc)

if counter % 2 == 1:
    for i in range(N):
        if a_list[i] < 0:
            a_list[i] *= -1
    min_mun = min(a_list)
    ans = sum(a_list) - 2*min_mun
    print(ans)