def decide_play(lst):
	"""
	This function will return the boolean to control whether user should continue the game.
	----------------------------------------------------------------------------
	:param lst: (list) a list stores the input alphabet.
	:return: (bool) if the input character is alphabet and if only one character is in the string.
	"""
	if len(lst) == 4:
		for char in lst:
			if char.isalpha() and len(char) == 1:
				pass
			else:
				return False
		return True
	else:
		return False