letters = "abcdefghijklmnopqrstuvwxyz"
backwards = letters[::-1]
print("Backwards:", backwards)

qpo = letters[16:13:-1]
print("QPO:", qpo)

edcba = letters[4::-1]
# edcba = backwards[21:]
print("EDCBA:", edcba)

zyxwvuts = letters[:-9:-1]
print("ZYXWVUTS:", zyxwvuts)
