Split in Three

N = int(input())
full = 0
for i in range(1, N+1):
	 full += i

if full % 3 != 0:
	print('IMPOSSIBLE')
	raise SystemExit

tar = full // 3

from functools import lru_cache

def f(tar, avail):
	if tar == 0: yield avail

	for i in range(N):
		if i + 1 > tar: break
		if avail & (1<<i) != 0:
			yield from f(tar-(i+1), avail ^ (1<<i))


def coll(chosen):
	return set(i+1 for i in range(N) if chosen & (1<<i))


A = (1<<N)-1
for avail1 in f(tar-1, A):
	chosen1 = A ^ avail1

	for avail2 in f(tar, avail1):
		chosen2 = avail1 ^ avail2
		chosen3 = avail2

		res = [1] * N
		for i in range(N):
			if chosen2 & (1<<i) != 0:
				res[i] = 2
			elif chosen3 & (1<<i) != 0:
				res[i] = 3

		print(' '.join(map(str, res)))
		raise SystemExit

print('IMPOSSIBLE')

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 1, 2

Verdict: ACCEPTED

Test 3

Group: 1, 2

Verdict: ACCEPTED

Test 4

Group: 1, 2

Verdict: ACCEPTED

Test 5

Group: 1, 2

Verdict: ACCEPTED

Test 6

Group: 1, 2

Verdict: ACCEPTED

Test 7

Group: 1, 2

Verdict: ACCEPTED

Test 8

Group: 1, 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 2

Verdict: ACCEPTED