# warmup 1: (final callenge from class 26 string practice) 
# Write a function that returns the number of
# vowels in a given string s. Hint: use the `in` operator.
# Another hint: see count_upper_case() in the study guide.
def count_vowels(s):
    pass

# warmup 2: (final challenge from class 27 string methods)
# Write this function
def print_to_Dickinson(s):
    """If s contains the string 'Dickinson', print up to and including the last
    occurrence of 'Dickinson'. Otherwise, print 'not found'."""
    pass