Buggy python submission (verdict: Runtime Error):
while True:
  n, k = map(int, input().split())
  s = input().rstrip()

  def findEx(s, f, pos, notfound):
    pos = s.find(f, pos)
    if pos == -1:
      pos = notfound
    return pos

  ans = 0
  left = 0
  right = 0
  while right < n:
      if k > 0:
          right = findEx(s, '01', right, n-1) + 1
          k = k - 1
          right = findEx(s, '10', right, n-1) + 1
          ans = max(ans, right - left)
      else:
          left = findEx(s, '01', left, n-1) + 1
          k = k + 1

  print(ans)

  if input() == "":
    break

Fixed submission:
n, k = map(int, input().split())
s = input().rstrip()


#n, k = 5, 3
#s = "00010"

m = 0
cur_s = cur_e = 0

while True:
  while cur_e < n and s[cur_e] == '1':
    cur_e+=1
  
  if k <= 0 or cur_e >= n:
    wm = cur_e - cur_s
    if wm > m:
      m = wm
      
    if cur_e >= n:
      break
 
    while cur_s < n and s[cur_s] == '1':
      cur_s+=1
    while cur_s < n and s[cur_s] == '0':
      cur_s+=1
    k+=1

  if k > 0:
    while cur_e < n and s[cur_e] == '0':
      cur_e+=1
    k-=1
    
print(m)

Buggy python submission (verdict: Runtime Error):
n, k = map(int, input().split())
s = input().rstrip()
ans = 1
left = 0
right = -1
pos = s.find('10', 0)
if pos == -1:
  i = n
else
  i = pos + 1

while i < n:
    if k > 0:
        pos = s.find('01', i)
        if pos == -1:
            i = n
            right = n - 1
        else:
            pos = s.find('10', pos + 1)
            if pos == -1:
                i = n
                right = n - 1
            else:
                right = pos
                i = pos + 1
        k = k - 1
        ans = max(ans, right - left + 1)
    else:
        pos = s.find('01', left)
        left = pos + 1
        k = k + 1

print(ans)

Fixed submission:
n, k = map(int, input().split())
s = input().rstrip()


#n, k = 5, 3
#s = "00010"

m = 0
cur_s = cur_e = 0

while True:
  while cur_e < n and s[cur_e] == '1':
    cur_e+=1
  
  if k <= 0 or cur_e >= n:
    wm = cur_e - cur_s
    if wm > m:
      m = wm
      
    if cur_e >= n:
      break
 
    while cur_s < n and s[cur_s] == '1':
      cur_s+=1
    while cur_s < n and s[cur_s] == '0':
      cur_s+=1
    k+=1

  if k > 0:
    while cur_e < n and s[cur_e] == '0':
      cur_e+=1
    k-=1
    
print(m)

Buggy python submission (verdict: Runtime Error):
n, k = map(int, input().split())
s = input().rstrip()

#s = "0001111011110"
#n, k = len(s), 1

s="1"+s

k_pt = 0
cur_tail = 0
for cur in range(1, n):

  cur_tail+=1

  if  s[cur-1] == '1' and s[cur] == '0':
    k_pt+=1

  if  s[cur_tail-1] == '0' and s[cur_tail] == '1':
    k_pt-=1

  if k_pt <= k:
      cur_tail-=1

print(cur-cur_tail)


Fixed submission:
n, k = map(int, input().split())
s = input().rstrip()


#n, k = 5, 3
#s = "00010"

m = 0
cur_s = cur_e = 0

while True:
  while cur_e < n and s[cur_e] == '1':
    cur_e+=1
  
  if k <= 0 or cur_e >= n:
    wm = cur_e - cur_s
    if wm > m:
      m = wm
      
    if cur_e >= n:
      break
 
    while cur_s < n and s[cur_s] == '1':
      cur_s+=1
    while cur_s < n and s[cur_s] == '0':
      cur_s+=1
    k+=1

  if k > 0:
    while cur_e < n and s[cur_e] == '0':
      cur_e+=1
    k-=1
    
print(m)

Buggy python submission (verdict: Runtime Error):

n, k = map(int, input().split())
s = input().rstrip()
m = 0
cur_s = cur_e = 0

while True:
  while s[cur_e] == '1':
    cur_e++
  
  if k <= 0 or cur_e >= n:
    wm = cur_e - cur_s
    if wm < m:
      m = wm
      
    if cur_e >= n:
      break
 
    while s[cur_s] == '1':
      cur_s++
    while s[cur_s] == '0':
      cur_s++
    k++

  if k > 0:
    while s[cur_e] = '0':
      cur_e++
    k--
    
print(m)


Fixed submission:
n, k = map(int, input().split())
s = input().rstrip()


#n, k = 5, 3
#s = "00010"

m = 0
cur_s = cur_e = 0

while True:
  while cur_e < n and s[cur_e] == '1':
    cur_e+=1
  
  if k <= 0 or cur_e >= n:
    wm = cur_e - cur_s
    if wm > m:
      m = wm
      
    if cur_e >= n:
      break
 
    while cur_s < n and s[cur_s] == '1':
      cur_s+=1
    while cur_s < n and s[cur_s] == '0':
      cur_s+=1
    k+=1

  if k > 0:
    while cur_e < n and s[cur_e] == '0':
      cur_e+=1
    k-=1
    
print(m)