s1 = "python"
s2 = "typhoon"
common = set(s1) & set(s2)
print("".join(common))

def find_common_characters(string1, string2):
    """
    Finds and returns a set of common characters between two strings.

    Args:
        string1 (str): The first input string.
        string2 (str): The second input string.

    Returns:
        set: A set containing the common characters.
    """
    set1 = set(string1)  # Convert the first string to a set of its characters
    set2 = set(string2)  # Convert the second string to a set of its characters

    common_chars = set1.intersection(set2)  # Find the intersection of the two sets
    return common_chars

# Get input from the user
str1 = input("Enter the first string: ")
str2 = input("Enter the second string: ")

# Find the common characters
common = find_common_characters(str1, str2)

# Print the result
if common:
    print(f"The common characters are: {', '.join(sorted(list(common)))}")
else:
    print("There are no common characters between the two strings.")