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
#include <bits/stdc++.h>
using namespace std;
const long long int mod = 1e9 + 7;
const int INF = 0x7f7f7f7f;
const long double eps = 1e-9;
const int MAXN = 100010;
int nxt[MAXN];
int main() {
  string s;
  cin >> s;
  stack<pair<char, int> > st;
  memset(nxt, -1, sizeof nxt);
  for (int i = 0; s[i]; i++) {
    if (s[i] == '(' or s[i] == '[')
      st.push(make_pair(s[i], i));
    else {
      if (st.empty())
        continue;
      else if ((st.top().first == '(' and s[i] == ')') or
               (st.top().first == '[' and s[i] == ']')) {
        pair<char, int> p = st.top();
        st.pop();
        nxt[p.second] = i;
      } else
        st.push(make_pair(s[i], i));
    }
  }
  int prev = -11;
  vector<pair<int, string> > v;
  for (int i = 0; i < (int)(s.size());) {
    if (nxt[i] == -1) {
      i++;
      continue;
    }
    int j = nxt[i];
    int k = i;
    string temp;
    int tempans = 0;
    while (i <= j) {
      tempans += s[i] == '[';
      temp += s[i];
      i++;
    }
    if (prev == k - 1) {
      pair<int, string> p = v.back();
      v.pop_back();
      v.push_back(make_pair(p.first + tempans, p.second + temp));
    } else
      v.push_back(make_pair(tempans, temp));
    prev = j;
  }
  if (!(int)(v.size())) {
    cout << 0 << '\n';
    return 0;
  }
  sort(v.rbegin(), v.rend());
  cout << v[0].first << '\n' << v[0].second << '\n';
  return 0;
}
