def getEncryptedLetter(s, k, isUpper=True):
    startChar = "A" if isUpper else "a"
    endChar = "Z" if isUpper else "z"
    num = ord(s)
    k = k % 26
    if num + k > ord(endChar):
        diff = (num + k) - ord(endChar)
        new_num = ord(startChar) + diff - 1
    else:
        new_num = num + k
    return chr(new_num)
    
    
def caesarCipher(s, k):
    # Write your code here
    excrypted_str = ""
    for i in s:
        if ("A" <= i <= "Z") or ("a" <= i <= "z"):
            excrypted_str += getEncryptedLetter(i, k, "A" <= i <= "Z")
            continue
        excrypted_str += i
    return excrypted_str