def sliding(iterable,window=1):
	# pairwise('ABCDEFG') --> AB BC CD DE EF FG
	from itertools import tee
	a, b = tee(iterable)
	IT = [  ]
	for _ in range(window):
		next(b, None)
	return zip(a, b)

def sliding_window(iterable, n):
	from collections import deque
	from itertools import islice
	# sliding_window('ABCDEFG', 4) -> ABCD BCDE CDEF DEFG
	it = iter(iterable)
	window = deque(islice(it, n), maxlen=n)
	#window = deque(it, maxlen=n)
	if len(window) == n:
		yield tuple(window)
	for x in it:
		window.append(x)
		yield tuple(window)

import sys

print([t for t in sliding_window(map(lambda x: int(x[:-1]), sys.stdin.readlines()),4)])
#print(a for a in sliding(map(lambda x: int(x[:-1]), sys.stdin.readlines()),3))