def main():
    """
    Create a program that randomly generates simple addition problems for the user,
    reads in the answer from the user, and then checks to see if they got it right or wrong,
    until the user appears to have mastered the material and print a message to congratulate the user.
    """

    answers_right = 0

    while answers_right < 3:

        ran_number_1 = random.randint(10, 99)
        ran_number_2 = random.randint(10, 99)
        solution = ran_number_1 + ran_number_2

        print(f"What is {ran_number_1} + {ran_number_2}?")
        user_answer = int(input("Your answer: "))

        if user_answer == solution:
            answers_right += 1
            print(f"Correct. You've gotten {answers_right} correct in a row.")
        elif user_answer != solution:
            answers_right = 0
            print(f"Incorrect. The expected answer is {solution}.")
        else:
            print("Invalid Response.")

Error:
Traceback (most recent call last):
  File "C:/Users/Carlo/Documents/Standford Class/Assignment2/khansole_academy.py", line 47, in <module>
    main()
  File "C:/Users/Carlo/Documents/Standford Class/Assignment2/khansole_academy.py", line 26, in main
    user_answer = int(input("Your answer: "))
ValueError: invalid literal for int() with base 10: 'qer'

try:
   correct_answer = solution == int(user_answer)
except ValueError:
   correct_anser = False

if correct_anser:
   # do correct answer stuff
else:
   # do incorrect answer stuff