Лиза Логина

N = int(input())

for _ in range(3):
        chet = 0
	nechet = 0
	for i in str(N):
		if int(i) % 2:
			nechet += 1
		else: 
			chet += 1

	if chet > nechet:
		N = N << 1 + 1
	elif chet < nechet:
		N = N << 1
	elif N % 2:
		N = N << 1 + 1
	else:
		N = N << 1

print(N)