def caesarCipher(s, k):
    alphabet = 'abcdefghijklmnopqrstuvwxyz'
    result = ''
    
    for char in s:
        if char.lower() in alphabet:
            idx = alphabet.index(char.lower()) + k
            c = alphabet[idx % len(alphabet)]
            
            if char.isupper():
                result += c.upper()
            else:
                result += c
                
        else:
            result += char
            
    return result