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 int maxn = 1e5 + 5;
int sum[maxn];
string s;
int answer, ansl, ansr;
int n;
int sts;
int st[maxn];
bool was;
inline void check(int l, int r) {
  if (l >= r) return;
  r++;
  if (sum[r] - sum[l] > answer || (!was)) {
    answer = sum[r] - sum[l];
    ansl = l;
    ansr = r;
    was = true;
  }
}
inline bool match(char a, char b) {
  return (a == '(' && b == ')') || (a == '[' && b == ']');
}
int main() {
  cin >> s;
  n = s.length();
  memset(sum, 0, sizeof(sum));
  sum[0] = 0;
  for (int i = 1; i <= n; i++) {
    sum[i] = sum[i - 1];
    if (s[i - 1] == '[') sum[i]++;
  }
  answer = 0;
  ansl = 0;
  ansr = 0;
  sts = 0;
  was = false;
  int begin = 0;
  for (int i = 0; i < n; i++) {
    if (s[i] == '(' || s[i] == '[') {
      if (sts == 0)
        check(begin, i - 1);
      else
        check(st[sts - 1] + 1, i - 1);
      st[sts] = i;
      sts++;
    } else if (sts == 0) {
      check(begin, i - 1);
      begin = i + 1;
    } else if (match(s[st[sts - 1]], s[i])) {
      check(st[sts - 1], i);
      sts--;
    } else {
      check(st[sts - 1] + 1, i - 1);
      sts = 0;
      begin = i + 1;
    }
  }
  if (sts != 0)
    check(st[sts - 1] + 1, n - 1);
  else
    check(begin, n - 1);
  cout << answer << endl;
  for (int i = ansl; i < ansr; i++) cout << s[i];
  cout << endl;
  return 0;
}
