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
"""
Algorithm to determine the most common words in a given string
"""

def most_common_words(string):
    # split the string on whitespace
    words = string.split()

    # create a dictionary to store the count of each word 
    word_count = {}

    # for each word, add it to the dictionary or increment the count 
    for word in words:
        if word not in word_count:
            word_count[word] = 1
        else:
            word_count[word] += 1

    # convert the dictionary into a list of tuples (word, count)
    count_list = sorted(word_count.items(), key=lambda x: x[1], reverse=True)

    return count_list[0][0]

if __name__ == '__main__':
    string = 'Hello world. This is a sentence.'
    print('The most common word is:', most_common_words(string))
user
The most common word is: Hello
assistant