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;
template <class T>
T cdiv(T num, T den) {
  return (num / den) + (num % den > 0);
}
template <typename TH>
void _dbg(const char* sdbg, TH h) {
  cerr << sdbg << "=" << h << "\n";
}
template <typename TH, typename... TA>
void _dbg(const char* sdbg, TH h, TA... t) {
  while (*sdbg != ',') cerr << *sdbg++;
  cerr << "=" << h << ",";
  _dbg(sdbg + 1, t...);
}
template <class t>
t mag(t a) {
  return a > 0 ? a : -a;
}
std::ifstream term("/dev/tty");
string tempstring;
int tc = 1;
string s, tp;
vector<int> en, dp;
int escape() {
  cin >> tp;
  s = ' ' + tp;
  stack<int> st;
  en.resize(s.size(), -1);
  dp.resize(s.size(), -1);
  for (int i = 1; i < s.size(); i++) {
    if (s[i] == '(' or s[i] == '[') {
      st.push(i);
    } else {
      if (st.empty()) continue;
      if (s[i] == ')' and s[st.top()] == '(') {
        en[st.top()] = i;
        st.pop();
        continue;
      }
      if (s[i] == ')') {
        st = stack<int>();
      }
      if (s[i] == ']') {
        if (s[st.top()] == '[') {
          en[st.top()] = i;
          st.pop();
          continue;
        }
        st = stack<int>();
      }
    }
  }
  for (int r = s.size() - 1; r > 0; r--) {
    dp[r] = en[r];
    if (en[r] != -1 and en[r] + 1 < s.size() and dp[en[r] + 1] != -1) {
      dp[r] = dp[en[r] + 1];
    }
  }
  vector<int> cnt;
  int cur = 0;
  for (int i = 0; i < s.size(); i++) {
    cur += (s[i] == '[');
    cnt.push_back(cur);
  }
  int maxi = 0;
  for (int i = 1; i < s.size(); i++) {
    if (dp[i] != -1 and cnt[dp[i]] - cnt[i - 1] > maxi) {
      maxi = cnt[dp[i]] - cnt[i - 1];
    }
  }
  cout << maxi << '\n';
  ;
  ;
  if (maxi == 0) {
    return 0;
  }
  for (int i = 1; i < s.size(); i++) {
    if (dp[i] != -1 and cnt[dp[i]] - cnt[i - 1] == maxi) {
      for (int c = i; c <= dp[i]; c++) {
        cout << s[c];
      }
      return 0;
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  while (tc--) escape();
}
