cs50p little professor question, my code get rejected because of wrong level . anyone knows why?

Question

this is my code for the little professor problem , the task is when the level is not 1 ,2 or 3 repromt , this is what the code does but still get reject for the level repromt

:) professor.py exists
:( Little Professor rejects level of 0
    expected program to reject input, but it did not
:( Little Professor rejects level of 4
    expected program to reject input, but it did not
:( Little Professor rejects level of "one"
    expected program to reject input, but it did not
:) Little Professor accepts valid level
:) At Level 1, Little Professor generates addition problems using 0–9
:) At Level 2, Little Professor generates addition problems using 10–99
:) At Level 3, Little Professor generates addition problems using 100–999
:) Little Professor generates 10 problems before exiting
:) Little Professor displays number of problems correct
:) Little Professor displays EEE when answer is incorrect
:) Little Professor shows solution after 3 incorrect attempts

import random

def main():
    while True:
        level = get_level()
        if level.isdigit() and int(level) in [1, 2, 3]:
            break
        else:
            ...

    score = 0
    valid = False
    for i in range(10):
        tries = 3
        valid = False
        intOne = generate_integer(level)
        intTwo = generate_integer(level)
        ans = input(str(intOne) + " + " + str(intTwo) + " = ")
        while not valid:
            res = intOne + intTwo
            if int(ans) != res:
                tries -= 1
                if tries == 0:
                    valid = True
                    print(str(res))
                else:a
                    print('EEE')
                    ans = game(intOne, intTwo)
            else:
                score += 1
                valid = True
    print(score)

def get_level():
    level = input('Level: ')
    return level

def game(intOne, intTwo):
         ans = input( str(intOne) + " + "+ str(intTwo) + " = " )
         return ans

def generate_integer(level):
    if level == "2":
        return random.randint(10, 99)
    if level == "3":
        return random.randint(100, 999)
    return random.randint(0, 10)


if __name__ == "__main__":
    main()