Buggy python submission (verdict: Runtime Error):
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            if ind == 0:
                line[ind] = counter1
            else:
                line[ind] = line[ind-1]+counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = line[ind-1] + counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        if ind == 0:
                line[ind] = counter1
        else:
                line[ind] = line[ind-1]+counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = line[ind-1] + counter0
        ind+=1
        

line[1:ind+1]  = line[:ind]   
line[0] = 0 
line = line[:ind+1]
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-(2*k+1)+1,2):
        chain = line[i+2*k+1]-line[i]
        #print(chain)
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Fixed submission:
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            if ind == 0:
                line[ind] = counter1
            else:
                line[ind] = line[ind-1]+counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = line[ind-1] + counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        if ind == 0:
                line[ind] = counter1
        else:
                line[ind] = line[ind-1]+counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = line[ind-1] + counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = line[ind-1]
        ind+=1
        
line[1:ind+1]  = line[:ind]   
line[0] = 0 
line = line[:ind+1]
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-2*k,2):
        chain = line[i+2*k+1]-line[i]
        #print(chain)
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Buggy python submission (verdict: Time Limit Exceeded):
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            line[ind] = counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        line[ind] = counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = 0
        ind+=1
line = line[:ind]    
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,ind-(2*k+1)+1,2):
        chain = sum(line[i:i+2*k+1])
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Fixed submission:
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            if ind == 0:
                line[ind] = counter1
            else:
                line[ind] = line[ind-1]+counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = line[ind-1] + counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        if ind == 0:
                line[ind] = counter1
        else:
                line[ind] = line[ind-1]+counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = line[ind-1] + counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = line[ind-1]
        ind+=1
        
line[1:ind+1]  = line[:ind]   
line[0] = 0 
line = line[:ind+1]
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-2*k,2):
        chain = line[i+2*k+1]-line[i]
        #print(chain)
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Buggy python submission (verdict: Time Limit Exceeded):
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            line[ind] = counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        line[ind] = counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = 0
        ind+=1
line = line[:ind]    
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-(2*k+1)+1,2):
        chain = sum(line[i:i+2*k+1])
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Fixed submission:
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            if ind == 0:
                line[ind] = counter1
            else:
                line[ind] = line[ind-1]+counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = line[ind-1] + counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        if ind == 0:
                line[ind] = counter1
        else:
                line[ind] = line[ind-1]+counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = line[ind-1] + counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = line[ind-1]
        ind+=1
        
line[1:ind+1]  = line[:ind]   
line[0] = 0 
line = line[:ind+1]
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-2*k,2):
        chain = line[i+2*k+1]-line[i]
        #print(chain)
        if chain>maxchain:
            maxchain=chain
    print(maxchain)

Buggy python submission (verdict: Time Limit Exceeded):
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            line[ind] = counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        line[ind] = counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = 0
        ind+=1
line = line[:ind]    
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    new = line.copy()
    for i in range(1,2*k+1):
        new = new+np.roll(line, i)
    new = new[2*k:]
    new = new[0::2]
    #print(new)
    print(new.max())

Fixed submission:
#4
n,k=map(int,input().split())
s=str(input())

import numpy as np
line = np.zeros([2*n,],dtype=np.int)
counter1 = 0
counter0 = 0
ind = 0
for i in range(n):
    c = int(s[i])
    if ind%2 ==0:
        if c == 1:
            counter1 += 1
        else:
            counter0 += 1
            if ind == 0:
                line[ind] = counter1
            else:
                line[ind] = line[ind-1]+counter1
            counter1 = 0
            ind+=1
    elif ind%2 ==1:
        if c == 0:
            counter0 += 1
        else:
            counter1 += 1
            line[ind] = line[ind-1] + counter0
            counter0 = 0
            ind+=1

if ind%2 ==0:
        if ind == 0:
                line[ind] = counter1
        else:
                line[ind] = line[ind-1]+counter1
        ind+=1
elif ind%2 ==1:
        line[ind] = line[ind-1] + counter0
        ind+=1
        
if ind%2 ==0:
        line[ind] = line[ind-1]
        ind+=1
        
line[1:ind+1]  = line[:ind]   
line[0] = 0 
line = line[:ind+1]
#print(line)

if (len(line)//2)<=k:
    print(n)
else:
    maxchain = 0
    for i in range(0,len(line)-2*k,2):
        chain = line[i+2*k+1]-line[i]
        #print(chain)
        if chain>maxchain:
            maxchain=chain
    print(maxchain)