# Source: https://rosettacode.org/wiki/Caesar_cipher#Python3
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 = "The quick brown fox jumped over the lazy dogs"
print(msg)
enc = caesar(msg, 11)
print(enc)
print(caesar(enc, 11, decode = True))
