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 INF = 1e9 + 23;
const int MOD = 1e9 + 7;
const int MAXN = 1e5 + 100;
int stk[MAXN];
int match[MAXN];
int sum[MAXN];
int main() {
  ios_base::sync_with_stdio(0);
  string s;
  cin >> s;
  int len = s.length();
  memset(match, -1, sizeof(match));
  int top = 0;
  for (int i = 0; i < len; ++i) {
    char need = '#';
    if (s[i] == '(' || s[i] == '[') {
      stk[top] = i;
      ++top;
    } else if (s[i] == ')') {
      need = '(';
    } else {
      need = '[';
    }
    if (need == '#') continue;
    if (top > 0 && s[stk[top - 1]] == need) {
      --top;
      match[i] = stk[top];
    } else {
      top = 0;
    }
  }
  for (int i = 0; i < len; ++i) {
    if (match[i] <= 0) continue;
    if (match[match[i] - 1] == -1) continue;
    match[i] = match[match[i] - 1];
  }
  for (int i = 0; i < len; ++i) {
    sum[i + 1] = sum[i] + (s[i] == '[');
  }
  int ans = 0, st = 0, end = 0;
  for (int i = 0; i < len; ++i) {
    if (match[i] == -1) continue;
    int le = match[i];
    int cur = sum[i + 1] - sum[le];
    if (cur > ans) {
      ans = cur;
      st = le;
      end = i;
    }
  }
  cout << ans << "\n";
  if (ans > 0) {
    stringstream ss;
    for (int i = st; i <= end; ++i) {
      ss << s[i];
    }
    cout << ss.str() << "\n";
  }
  return 0;
}
