Что выведет код?

def f(*args):
    result = []
    for x in args[0]:
        for w in args[1:]:
            if x in w:
                break
        else:
            result.append(x)
    return "".join(result)

s1, s2, s3= "hello", "hi", "good morning"
print(f(s1, s2, s3))