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;
char x[maxn];
int n, cntOpen[maxn], bracket[maxn];
vector<int> posNormal, posSquare;
int main() {
  scanf("%s", x);
  n = strlen(x);
  for (int i = 0; i < n; i++) {
    if (i) cntOpen[i] = cntOpen[i - 1];
    if (x[i] == '[') cntOpen[i]++;
  }
  memset(bracket, -1, sizeof(bracket));
  for (int i = 0; i < n; i++) {
    if (x[i] == '[')
      posSquare.push_back(i);
    else if (x[i] == '(')
      posNormal.push_back(i);
    else if (x[i] == ']') {
      if (posSquare.empty() ||
          (!posNormal.empty() && posNormal.back() > posSquare.back())) {
        posNormal.clear();
        posSquare.clear();
      } else {
        bracket[posSquare.back()] = i;
        posSquare.pop_back();
      }
    } else {
      if (posNormal.empty() ||
          (!posSquare.empty() && posSquare.back() > posNormal.back())) {
        posNormal.clear();
        posSquare.clear();
      } else {
        bracket[posNormal.back()] = i;
        posNormal.pop_back();
      }
    }
  }
  for (int i = 0; i < n; i++) {
    if (bracket[i] == -1) continue;
    while (bracket[i] + 1 < n && bracket[bracket[i] + 1] != -1)
      bracket[i] = bracket[bracket[i] + 1];
  }
  int size = 0, pos;
  for (int i = 0; i < n; i++)
    if (bracket[i] != -1) {
      int temp = cntOpen[bracket[i]];
      if (i) temp -= cntOpen[i - 1];
      if (temp <= size) continue;
      size = temp;
      pos = i;
    }
  printf("%d\n", size);
  if (size)
    for (int i = pos; i <= bracket[pos]; i++) printf("%c", x[i]);
  return 0;
}
