Java

        public static boolean checkPangram(String str) {
        // Normalize the string to lowercase and remove non-letter characters
        String normalizedStr = str.toLowerCase().replaceAll("[^a-z]", "");

        // Use a set to track unique letters
        HashSet<Character> lettersSet = new HashSet<>();

        // Add each character to the set
        for (char c : normalizedStr.toCharArray()) {
                lettersSet.add(c);
        }

        // Check if the size of the set is 26 (number of letters in the alphabet)
        return lettersSet.size() == 26;

}