fun caesar(s, k, decode: false):
    if decode:
        k = 26 - k
    result = ''
    for i in s.uppercase() where 65 <= ord(i) <= 90:
        result.push! char(ord(i) - 65 + k) mod 26 + 65
    return result

let message = "The quick brown fox jumped over the lazy dogs"
let encrypted = caesar(msg, 11)
let decrypted = caesar(enc, 11, decode: true)

print(message, encrypted, decrypted, sep: '\n')