def caesar(message):
    ciphertext = ''
    for ch in message:
        if(ch != ' '):
            ciphertext += chr(ord(ch)+3)
        else:
            ciphertext += ' '
    print("coded message: " + ciphertext)
    return ciphertext

def rev_caesar(ciphertext):
    cleartext = ''
    for ch in ciphertext:
        if(ch != ' '):
            cleartext += chr(ord(ch)-3)
        else:
            cleartext += ' '
    print("decoded message: " + cleartext)
    return cleartext