alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" numbers = "0123456789"
for letter1 in alphabet: for letter2 in alphabet: for letter3 in alphabet: for digit1 in numbers: for digit2 in numbers: for digit3 in numbers: for digit4 in numbers: code = letter1 + letter2 + letter3 + digit1 + digit2 + digit3 + digit4 print(code)