A bracket sequence is a string, containing only characters "(", ")", "[" and "]".

A correct bracket sequence is a bracket sequence that can be transformed into a correct arithmetic expression by inserting characters "1" and "+" between the original characters of the sequence. For example, bracket sequences "()[]", "([])" are correct (the resulting expressions are: "(1)+[1]", "([1+1]+1)"), and "](" and "[" are not. The empty string is a correct bracket sequence by definition.

A substring *s*[*l*... *r*] (1 ≤ *l* ≤ *r* ≤ |*s*|) of string *s* = *s*<sub class="lower-index">1</sub>*s*<sub class="lower-index">2</sub>... *s*<sub class="lower-index">|*s*|</sub> (where |*s*| is the length of string *s*) is the string *s*<sub class="lower-index">*l*</sub>*s*<sub class="lower-index">*l* + 1</sub>... *s*<sub class="lower-index">*r*</sub>. The empty string is a substring of any string by definition.

You are given a bracket sequence, not necessarily correct. Find its substring which is a correct bracket sequence and contains as many opening square brackets «[» as possible.
The first and the only line contains the bracket sequence as a string, consisting only of characters "(", ")", "[" and "]". It is guaranteed that the string is non-empty and its length doesn't exceed 10<sup class="upper-index">5</sup> characters.
#bracket sequence

def isPair(a, b):
	ret = False
	if a == '(':
		if b == ')':
			ret = True
			pass
	elif a == '[':
		if b == ']':
			ret = True
			pass
	return ret


seq = input()

stack = []

for i in range(0, len(seq)):
	if len(stack) != 0:
		if isPair(stack[-1], seq[i]):
			stack.pop()
		else:
			stack.append(seq[i])
	else:
		stack.append(seq[i])
	#print("%d : %a" %(i,stack))

if len(stack) == 0:
	print('1')
	print(seq)
else: 
	print('0')
	print('')