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
# Function to replace a given pattern with a different string
def replace_pattern(string, pattern, replacement):
    # Split string into list of words
    words = string.split()

    # Go through each word and replace the pattern
    for i in range(len(words)):
        if words[i] == pattern:
            words[i] = replacement

    # Return the modified string
    return ' '.join(words)


# Example
string = "Hello world!"
pattern = "Hello"
replacement = "Goodbye"
modified_string = replace_pattern(string, pattern, replacement)
print(modified_string) 
user
Goodbye world!
assistant