You are going to act as a Python interpreter. You will be given a valid python program below. Write down what you think the result of its execution would be. Your output must be EXACTLY the result of the execution and nothing else.
situation
system
def generate_fibonacci(length):
    # Initialize
    n1, n2 = 0, 1

    # Check if length is valid
    if length <= 0:
        print('Invalid length. Positive numbers only.')
    elif length == 1:
        print(n1)
    else:
        print(n1, n2, end=' ')
    
    # Generate sequence
    for i in range(2, length):
        n3 = n1 + n2
        print(n3, end=' ')
        n1 = n2
        n2 = n3

# Show output
generate_fibonacci(6)

user
0 1 1 2 3 5
assistant