input = open("./test.txt", "r")

for line in input:
  lastFourChar = []
  position = 0

  for char in line:
    position += 1
    lastFourChar.append(char)
    if (len(lastFourChar) > 3):
      # figure out comparison logic here
      print(lastFourChar)
      if (len(lastFourChar) == 4):
        lastFourChar.pop(0)