what is wrong with my code? every time i run it and input the set username it just makes me input my username again.

import time
username = "229796"
password = "rwqfsfascx"
yes = "update my system"
no = "continue to browser"
count = 0
while count < 3:
    user_choice = input('Enter username.')
    if user_choice == username:
        print('Remember this code: 17283645.')
        count = 4
    else: 
        print('Login unsuccessful, please try again.')
        count += 1
time.sleep(2) # Pause for 2 seconds
while count < 3:
    user_choice = input('Enter password.')
    if user_choice == password:
        print('Access granted.')
        count = 4
    else: 
        print('Login unsuccessful, please try again.')
        count += 1
print('Initiating system start. Please wait...')
time.sleep(3) # Pause for 3 seconds
print('System activated.')
time.sleep(1) # Pause for 1 second
user_choice = input('Would you like to update your system or continue directly to the browser?')
if user_choice == yes:
    print('Beginning system update. Please wait.')
    time.sleep(7) # Pause for 7 seconds
    print('System update complete. Opening browser.')
elif user_choice == no:
    print('Opening browser.')
else:
    print('Error 136. Please reload the system.')
time.sleep(2)
print('Browser activated. Opening .pjycs37 coding platform.')
time.sleep(2)
user_choice = input('Choose a programming language.')
print('Activating', user_choice, 'code platform.')
time.sleep(3)
print(user_choice, 'code platform activated.')