def caesar(s, k, decode = False):
    if decode: k = 26 - k
    return "".join([chr((ord(i) - 65 + k) % 26 + 65)
                for i in s.upper()
                if ord(i) >= 65 and ord(i) <= 90 ])

msg = "highams park school is great"
print msg
enc = caesar(msg, 11)
print enc