Buggy python submission (verdict: Time Limit Exceeded):
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    j = 1
    not_delete_list = []
    while True:
        if j >= len(concat_string) or i < 0:
            break
        if concat_string[i] != concat_string[j]:
            flags_delete[i] = True
            flags_delete[j] = True
            num_delete += 2
            
            if i == 0:
                i = j + 1
                j = i + 1
            else:
                if len(not_delete_list) > 0:
                    i = not_delete_list[-1]
                    not_delete_list = not_delete_list[:-1]
                    j = j + 1
                else:
                    i = j + 1
                    j = i + 1
        else:
            not_delete_list.append(i)
            i = j
            j = i + 1
            
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)

Buggy python submission (verdict: Time Limit Exceeded):
# coding: utf-8
# Your code here!

import copy
#import random

string = [x for x in input()]
#string = [random.randint(0, 1) for _ in range(int(1e5))]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    j = 1
    while True:
        if j >= len(concat_string) or i < 0:
            break
        if concat_string[i] != concat_string[j]:
            flags_delete[i] = True
            flags_delete[j] = True
            num_delete += 2
            
            if i == 0:
                i = j + 1
                j = i + 1
            else:
                if flags_delete[i] == False:
                    i = i - 1
                    j = j + 1
                else:
                    i = j + 1
                    j = i + 1
        else:
            i = j
            j = i + 1
            
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)

Buggy python submission (verdict: Runtime Error):
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    j = 1
    while i < len(concat_string) - 1:
        if concat_string[i] != concat_string[j]:
            flags_delete[i] = True
            flags_delete[j] = True
            num_delete += 2
            
            if i == 0:
                i = j + 1
                j = i + 1
            else:
                i = i - 1
                j = j + 1
        else:
            i = j
            j = i + 1
           
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)
        
        

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)

Buggy python submission (verdict: Runtime Error):
# coding: utf-8
# Your code here!

import copy

string = [*input()]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    j = 1
    while i < len(concat_string) - 1:
        if concat_string[i] != concat_string[j]:
            flags_delete[i] = True
            flags_delete[j] = True
            num_delete += 2
            
            if i == 0:
                i = j + 1
                j = i + 1
            else:
                i = i - 1
                j = j + 1
        else:
            i = j
            j = i + 1
           
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)
        
        

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)

Buggy python submission (verdict: Time Limit Exceeded):
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    while i < len(concat_string) - 1:
        if concat_string[i] != concat_string[i + 1]:
            flags_delete[i] = True
            flags_delete[i + 1] = True
            num_delete += 2
            i += 2
        else:
            i += 1
           
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)
        
        

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)

Buggy python submission (verdict: Runtime Error):
# coding: utf-8
# Your code here!

import copy

string = [*input()]

concat_string = copy.copy(string)
count = 0
while True:
    num_delete = 0
    flags_delete = [False] * len(string)
    
    i = 0
    while i < len(concat_string) - 1:
        if concat_string[i] != concat_string[i + 1]:
            flags_delete[i] = True
            flags_delete[i + 1] = True
            num_delete += 2
            i += 2
        else:
            i += 1
           
    if num_delete == 0:
        break
    
    count += num_delete
    concat_string = [concat_string[i] for i in range(len(concat_string)) if flags_delete[i] == False]

print(count)
        
        

Fixed submission:
# coding: utf-8
# Your code here!

import copy

string = [x for x in input()]

concat_string = copy.copy(string)
num_delete = 0

i = 0
j = 1
not_delete_list = []
while True:
    if j >= len(concat_string) or i < 0:
        break
    if concat_string[i] != concat_string[j]:
        num_delete += 2
        
        if i == 0:
            i = j + 1
            j = i + 1
        else:
            if len(not_delete_list) > 0:
                i = not_delete_list.pop(-1)
                j = j + 1
            else:
                i = j + 1
                j = i + 1
    else:
        not_delete_list.append(i)
        i = j
        j = i + 1


print(num_delete)