import sys
if len(sys.argv) < 2:
    print ("Usage: python 3letters.py <letter>")
    sys.exit(-1)
letter1 = sys.argv[1]

text = ""
file = open(f'{letter1}.txt', 'w')

for letter2 in range(ord('a'), ord('z') + 1):
    for letter3 in range(ord('a'), ord('z') + 1):
        text += letter1 + chr(letter2) + chr(letter3) + "\n"

file.write(text)
file.close()