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 = s1s2... s|s| (where |s| is the length of string s) is the string slsl + 1... sr. 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.

Input

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 105 characters.

Output

In the first line print a single integer — the number of brackets «[» in the required bracket sequence. In the second line print the optimal sequence. If there are more than one optimal solutions print any of them.

Examples

Input

([])


Output

1
([])


Input

(((


Output

0
s = raw_input()
br = []
val = [0]*(len(s))
for j in xrange(len(s)):
    i = s[j]
    if(i in "(["):
        br+=[j]
    if(i==']' and len(br)!=0 and s[br[-1]]=='['):
        val[br[-1]] = j
        br.pop()
    elif(i==']' and len(br)!=0 and s[br[-1]]=='('):
        br=[]
    elif(i==')' and len(br)!=0 and s[br[-1]]=='('):
        val[br[-1]] = j
        br.pop()
    elif(i==')' and len(br)!=0 and s[br[-1]]=='['):
        br=[]
con = []
i =0
while(i<len(s)):
    if(val[i]==0):
        i+=1
    else:
        xy = (i,val[i])
        con+=[xy]
        i = val[i]+1
comp=[]
if(len(con)!=0):
    comp = [con[0]]
    for i in con[1:]:
        x = comp.pop()
        if(x[-1]+1==i[0]):
            new_x = (x[0],i[1])
            comp+=[new_x]
        else:
            comp += [x,i]
cnt = 0
ans = ""
for i in comp:
    temp = s[i[0]:i[1]+1].count('[')
    if(temp>cnt):
        cnt = temp
        ans = s[i[0]:i[1]+1]
print cnt
print ans
