def caesarCipher(s, k):
        alphabet = "abcdefghijklmnopqrstuvwxyz"
        res = ""
        for c in s:
                is_upper = c.isupper()
                idx = alphabet.find(c.lower())
                if idx != -1:
                        new_idx = (idx + k) % 26
                        res += alphabet[new_idx].upper() if is_upper else alphabet[new_idx]
                else:
                        res += c

        return res