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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    arg = -1
    if A[0]>0:
        i=0
    else:
        i=1
    while i<len(A)-2:
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            arg = i
        i += 2
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        arg = len(A)-1
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    arg = -1
    if A[0]>0:
        i=0
    else:
        i=1
    while i<len(A)-2:
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            arg = i
        i += 2
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        arg = len(A)-1
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    arg = -1
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            arg = i
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        arg = len(A)-1
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    arg = -1
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            arg = i
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        arg = len(A)-1
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    arg = -1
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            args = i
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        arg = len(A)-1
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    args = [-1]
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            args = [i]
        elif m==s3:
            args.append(i)
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        args = [len(A)-1]
    elif m==s3:
        args.append(len(A)-1)
    arg = args[0]
    if arg==-1:
        B = [-A[0]+A[1]] + A[2:]
    elif arg==len(A)-1:
        B = A[:-2] + [A[-2]-A[-1]]
    else:
        B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
    return iter(B, cnt+1)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<2:
        return max(A)
    elif len(A)==2:
        return abs(A[0]) + abs(A[1])
    m = -A[0]+A[1]
    args = [-1]
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            args = [i]
        elif m==s3:
            args.append(i)
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        args = [len(A)-1]
    elif m==s3:
        args.append(len(A)-1)
    cands = []
    for arg in args:
        if arg==-1:
            B = [-A[0]+A[1]] + A[2:]
        elif arg==len(A)-1:
            B = A[:-2] + [A[-2]-A[-1]]
        else:
            B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
        cands.append(iter(B, cnt+1))
    return max(cands)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<3:
        return max(A)
    m = -A[0]+A[1]
    args = [-1]
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            args = [i]
        elif m==s3:
            args.append(i)
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        args = [len(A)-1]
    elif m==s3:
        args.append(len(A)-1)
    cands = []
    for arg in args:
        if arg==-1:
            B = [-A[0]+A[1]] + A[2:]
        elif arg==len(A)-1:
            B = A[:-2] + [A[-2]-A[-1]]
        else:
            B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
        cands.append(iter(B, cnt+1))
    return max(cands)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)

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

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        if comp=='0':
            arr.append(-cnt)
        else:
            arr.append(cnt)
        cnt = 1
        comp = s
if comp=='0':
    arr.append(-cnt)
else:
    arr.append(cnt)

def iter(A, cnt):
    if cnt>=K or len(A)<3:
        return max(A)
    m = -A[0]+A[1]
    args = [0]
    for i in range(len(A)-2):
        s3 = A[i] - A[i+1] + A[i+2]
        if m<s3:
            m = s3
            args = [i]
        elif m==s3:
            args.append(i)
    s3 = A[-2]-A[-1]
    if m<s3:
        m = s3
        args = [len(A)-1]
    elif m==s3:
        args.append(len(A)-1)
    cands = []
    for arg in args:
        if arg==0:
            B = [-A[0]+A[1]] + A[2:]
        elif arg==len(A)-1:
            B = A[:-2] + [A[-2]-A[-1]]
        else:
            B = A[:arg] + [A[arg] - A[arg+1] + A[arg+2]] + A[arg+3:]
        cands.append(iter(B, cnt+1))
    return max(cands)


print(iter(arr, 0))

Fixed submission:
N, K = map(int, input().split())
S = input()

arr = []
cnt = 0
comp = S[0]
for s in S:
    if s==comp:
        cnt += 1
    else:
        arr.append(cnt)
        cnt = 1
        comp = s
arr.append(cnt)

if len(arr)<3:
    print(sum(arr))
else:
    if S[0]=='1':
        L = (len(arr)+1)//2 - K +1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)+1])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - (arr[2*(l-1)]+arr[2*l-1]) + sum(arr[2*(l-1+K)+1 : min(2*(l+K)+1, len(arr))])
            ans = max(tmp, ans)
    else:
        L = (len(arr)+1)//2 - K + 1
        l = 0
        tmp = sum(arr[2*l:2*(l+K)])
        ans = tmp
        for l in range(1, L):
            tmp = tmp - sum(arr[max(0,2*l-3) : 2*l-1]) + sum(arr[2*(l+K-1): min(2*(l+K), len(arr))])
            ans = max(tmp, ans)
            
    print(ans)