pda_stack = []

def pda(input_string):
	# Convert string to list
	input_string = list(input_string)
	# Reverse to achieve a stack implementation
	input_string.reverse()

	if not input_string[-1] == 'a':
		print("Rejected")
		return

	while len(input_string) > 0 and input_string[-1] == 'a':
		pda_stack.append('a')
		input_string.pop()

	last_part(input_string)

def last_part(input_string):
	if len(input_string) > 0 and input_string[-1] == 'b':
		input_string.pop()
		if len(input_string) > 0 and input_string[-1] == 'b':
			input_string.pop()
			if len(pda_stack) > 0 and pda_stack.pop() == 'a':
				if len(input_string) == 1 and input_string[-1] == 'b':
					input_string.pop()
					print("Accepted!")
					return
				elif len(input_string) > 0 and input_string[-1] == 'b':
					input_string.pop()
					last_part(input_string)
	print("Rejected")


if __name__ == "__main__":
	input_string = raw_input("Enter input string: ")

	pda(input_string)