print("Two-letter domain names:")

letter1 = "a"
letter2 = "?"
while letter1 <= "z":  # Outer loop
    letter2 = "a"
    while letter2 <= "z":  # Inner loop
        print(f"{letter1}{letter2}.com")
        letter2 = chr(ord(letter2) + 1)
    letter1 = chr(ord(letter1) + 1)