def pangrams(s: str):
    # Time complexity: O(n)
    # Space complexity (ignoring input): O(1)
    bit_mask = 0
    for letter in s.lower():
        if (letter <= "z") and (letter >= "a"):
            bit_pos = ord(letter) - ord("a")
            bit_mask |= 1 << bit_pos

    if bit_mask == (1 << 26) - 1:
        return "pangram"
    return "not pangram"


def pangrams_not_elegant(s: str):
    # Time complexity: O(n)
    # Space complexity (ignoring input): O(1)
    dict_letters = {}
    for letter in s.lower():
        if (letter <= "z") and (letter >= "a") and (letter not in dict_letters):
            dict_letters[letter] = 1

    if len(dict_letters) == 26:
        return "pangram"

    return "not pangram"