Buggy python submission (verdict: Runtime Error):
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    if k > 0:
        score += (cum_zeros[i+k-1] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k]
    if max_score < score:
        max_score = score

print(max_score)


Fixed submission:
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    if k > 0:
        score += (cum_zeros[i+k-1] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k-1]
    if max_score < score:
        max_score = score

print(max_score)

Buggy python submission (verdict: Runtime Error):
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    score += (cum_zeros[i+k] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k]
    if max_score < score:
        max_score = score

print(max_score)

Fixed submission:
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    if k > 0:
        score += (cum_zeros[i+k-1] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k-1]
    if max_score < score:
        max_score = score

print(max_score)

Buggy python submission (verdict: Time Limit Exceeded):
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

max_score = 0
for i in range(n_zeros - k + 1):
    score = sum(ones[i:i+k+1]) + sum(zeros[i:i+k])
    if max_score < score:
        max_score = score

print(max_score)


Fixed submission:
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    if k > 0:
        score += (cum_zeros[i+k-1] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k-1]
    if max_score < score:
        max_score = score

print(max_score)

Buggy python submission (verdict: Time Limit Exceeded):
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

if k > len(zeros):
    k = len(zeros)

scores = []
for i in range(len(zeros) - k + 1):
    scores.append(sum(ones[i:i+k+1]) + sum(zeros[i:i+k]))

print(max(scores))


Fixed submission:
n, k = map(int, input().split())
seq = [bool(int(c)) for c in input()]

ones = []
if seq[0] is False:
    ones.append(0)
zeros = []
state = True
cnt = 0
for i, c in enumerate(seq):
    if i == 0:
        state = c
        cnt = 1
        continue

    if c == state:
        cnt += 1
    else:
        if state:
            ones.append(cnt)
        else:
            zeros.append(cnt)
        cnt = 1
        state = c

if state is True:
    ones.append(cnt)
else:
    ones.append(0)
    zeros.append(cnt)

# print(ones)
# print(zeros)

n_zeros = len(zeros)

k = min(k, n_zeros)

cum_ones = []
for i, num in enumerate(ones):
    if i == 0:
        cum_ones.append(num)
        continue
    cum_ones.append(num + cum_ones[-1])
cum_zeros = []
for i, num in enumerate(zeros):
    if i == 0:
        cum_zeros.append(num)
        continue
    cum_zeros.append(num + cum_zeros[-1])

max_score = 0
for i in range(n_zeros - k + 1):
    score = 0
    score += (cum_ones[i+k] - cum_ones[i-1]) if i > 0 else cum_ones[i+k]
    if k > 0:
        score += (cum_zeros[i+k-1] - cum_zeros[i-1]) if i > 0 else cum_zeros[i+k-1]
    if max_score < score:
        max_score = score

print(max_score)