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 count_words(sentence):
    # split the sentence on whitespace
    words = sentence.split()
    
    # return the length of the resulting list
    return len(words)
    
sentence = 'This is a test sentence.'

# count the number of words
num_words = count_words(sentence)

print('Number of words:', num_words)
user
Number of words: 5
assistant