def city_country(city, country):
    """Return a string like 'Santiago, Chile'."""
    return f"{city.title()}, {country.title()}"

city = city_country('santiago', 'chile')
print(city)

city = city_country('ushuaia', 'argentina')
print(city)

city = city_country('longyearbyen', 'svalbard')
print(city)