Problem:
Snuke stands on a number line. He has L ears, and he will walk along the line continuously under the following conditions:    * He never visits a point with coordinate less than 0, or a point with coordinate greater than L.   * He starts walking at a point with integer coordinate, and also finishes walking at a point with integer coordinate.   * He only changes direction at a point with integer coordinate.  Each time when Snuke passes a point with coordinate i-0.5, where i is an integer, he put a stone in his i-th ear.  After Snuke finishes walking, Ringo will repeat the following operations in some order so that, for each i, Snuke's i-th ear contains A_i stones:    * Put a stone in one of Snuke's ears.   * Remove a stone from one of Snuke's ears.  Find the minimum number of operations required when Ringo can freely decide how Snuke walks.

Incorrect submission (verdict: Wrong Answer):
# D
L = int(input())
A_list = [0]*L
for i in range(L):
    A_list[i] = int(input())


left_min = 0
left = 0
left_min_i_odd = -1
for i in range(L):
    if A_list[i] == 0:
        left -= 1
    else:
        if A_list[i] % 2 == 1:
            left += A_list[i]
        else:
            left += A_list[i] - 1
    if left < left_min:
        left_min = left
        left_min_i_odd = i
        
if left_min_i_odd == -1:
    left_min_odd = 0
else:
    left_min_odd = sum(A_list[:(left_min_i_odd+1)])


left_min = 0
left = 0
left_min_i_even = -1
for i in range(L):
    if A_list[i] == 0:
        left -= 2
    else:
        if A_list[i] % 2 == 0:
            left += A_list[i]
        else:
            left += A_list[i] - 1
    if left < left_min:
        left_min = left
        left_min_i_even = i
        
if left_min_i_even == -1:
    left_min_even = 0
else:
    left_min_even = sum(A_list[:(left_min_i_even+1)])


right_min = 0
right = 0
right_min_i_odd = L
for i in range(L-1, -1, -1):
    if A_list[i] == 0:
        right -= 1
    else:
        if A_list[i] % 2 == 1:
            right += A_list[i]
        else:
            right += A_list[i] - 1
    if right < right_min:
        right_min = right
        right_min_i_odd = i
        
if right_min_i_odd == L:
    right_min_odd = 0
else:
    right_min_odd = sum(A_list[right_min_i_odd:])
        

right_min = 0
right = 0
right_min_i_even = L
for i in range(L-1, -1, -1):
    if A_list[i] == 0:
        right -= 2
    else:
        if A_list[i] % 2 == 0:
            right += A_list[i]
        else:
            right += A_list[i] - 1
    if right < right_min:
        right_min = right
        right_min_i_even = i
        
if right_min_i_even == L:
    right_min_even = 0
else:
    right_min_even = sum(A_list[right_min_i_even:])

0
偶奇0
偶0
奇0
0

res_list_8 = []

for p in range(4):
    if p == 0:
        left_min = left_min_even
        left_i = left_min_i_even
        right_min = right_min_even
        right_i = right_min_i_even
    elif p == 1:
        left_min = left_min_even
        left_i = left_min_i_even
        right_min = right_min_odd
        right_i = right_min_i_odd
    elif p == 2:
        left_min = left_min_odd
        left_i = left_min_i_odd
        right_min = right_min_odd
        right_i = right_min_i_odd
    else:
        left_min = left_min_odd
        left_i = left_min_i_odd
        right_min = right_min_even
        right_i = right_min_i_even
    
    res1 = left_min + right_min
    left_min = 0
    
    for i in range(left_i +1, right_i):
        if A_list[i] == 0:
            res1 += 2
        else:
            res1 += A_list[i] % 2
    left = 0
    right = 0
    left_min = 0
    right_min = 0

    for i in range(left_i +1, right_i):
        if A_list[i] == 0:
            left -= 1
        elif A_list[i] % 2 == 0:
            left += 1
        else:
            left -= 1
        if left < left_min:
            left_min = left
            if i == right_i - 1:
                right_min = 1

    if right_min != 1:
        for i in range(right_i-1, left_i, -1):
            if A_list[i] == 0:
                right -= 1
            elif A_list[i] % 2 == 0:
                right += 1
            else:
                right -= 1
            if right < right_min:
                right_min = right
    else:
        right_min = 0
        
    res1 += (left_min+right_min)

    res_list_8.append(res1)
    
0
for p in range(4):
    if p == 0:
        left_min = left_min_even
        left_i = left_min_i_even
        right_min = right_min_even
        right_i = right_min_i_even
    elif p == 1:
        left_min = left_min_even
        left_i = left_min_i_even
        right_min = right_min_odd
        right_i = right_min_i_odd
    elif p == 2:
        left_min = left_min_odd
        left_i = left_min_i_odd
        right_min = right_min_odd
        right_i = right_min_i_odd
    else:
        left_min = left_min_odd
        left_i = left_min_i_odd
        right_min = right_min_even
        right_i = right_min_i_even
    
    res1 = left_min + right_min
    left_min = 0
    
    for i in range(left_i +1, right_i):
        res1 += (A_list[i]+1) % 2
    left = 0
    right = 0
    left_min = 0
    right_min = 0

    for i in range(left_i +1, right_i):
        if A_list[i] == 0:
            left += 1
        elif A_list[i] % 2 == 0:
            left -= 1
        else:
            left += 1
        if left < left_min:
            left_min = left
            if i == right_i - 1:
                right_min = 1

    if right_min != 1:
        for i in range(right_i-1, left_i, -1):
            if A_list[i] == 0:
                right += 1
            elif A_list[i] % 2 == 0:
                right -= 1
            else:
                right += 1
            if right < right_min:
                right_min = right
    else:
        right_min = 0

    res1 += (left_min+right_min)

    res_list_8.append(res1)
    


print(min(res_list_8[4:]))

Fixed, accepted submission:
# D
L = int(input())
A_list = [0]*L
for i in range(L):
    A_list[i] = int(input())
    
DP = [0]*5
for i in range(L):
    r0 = A_list[i]
    r1 = (A_list[i] + 1) % 2
    if A_list[i] == 0:
        r2 = 2
    else:
        r2 = A_list[i] % 2
        
    DP[4] = min(DP[0], DP[1], DP[2], DP[3], DP[4]) + r0
    DP[3] = min(DP[0], DP[1], DP[2], DP[3]) + r2
    DP[2] = min(DP[0], DP[1], DP[2]) + r1
    DP[1] = min(DP[0], DP[1]) + r2
    DP[0] = DP[0] + r0
    
print(min(DP))