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;
int main() {
  string s;
  cin >> s;
  int n = s.size();
  int c[n];
  int d[n];
  for (int i = 0; i < n; i++) {
    c[i] = -2;
    d[i] = -2;
  }
  stack<pair<int, int>> st;
  for (int i = 0; i < n; i++) {
    if (s[i] == '(') {
      st.push(make_pair(1, i));
    } else if (s[i] == '[') {
      st.push(make_pair(2, i));
    } else if (s[i] == ')') {
      if (st.empty() || st.top().first != 1) {
        c[i] = -1;
        d[i] = -1;
        while (!st.empty()) {
          st.pop();
        }
      } else {
        d[i] = st.top().second;
        st.pop();
        if (d[i] == 0) {
          c[i] = 0;
        } else if (s[d[i] - 1] == '(' || s[d[i] - 1] == '[') {
          c[i] = d[i];
        } else if (c[d[i] - 1] == -1) {
          c[i] = d[i];
        } else {
          c[i] = c[d[i] - 1];
        }
      }
    } else {
      if (st.empty() || st.top().first != 2) {
        c[i] = -1;
        d[i] = -1;
        while (!st.empty()) {
          st.pop();
        }
      } else {
        d[i] = st.top().second;
        st.pop();
        if (d[i] == 0) {
          c[i] = 0;
        } else if (s[d[i] - 1] == '(' || s[d[i] - 1] == '[') {
          c[i] = d[i];
        } else if (c[d[i] - 1] == -1) {
          c[i] = d[i];
        } else {
          c[i] = c[d[i] - 1];
        }
      }
    }
  }
  int pre[n];
  if (s[0] == '[') {
    pre[0] = 1;
  } else {
    pre[0] = 0;
  }
  for (int i = 1; i < n; i++) {
    if (s[i] == '[') {
      pre[i] = pre[i - 1] + 1;
    } else {
      pre[i] = pre[i - 1];
    }
  }
  int maxi = 0;
  int point1 = 0;
  for (int i = 0; i < n; i++) {
    if (c[i] == -2 || c[i] == -1) {
      continue;
    } else {
      int z = 0;
      if (c[i] == 0) {
        z = pre[i];
      } else {
        z = pre[i] - pre[c[i] - 1];
      }
      if (z > maxi) {
        point1 = i;
        maxi = z;
      }
    }
  }
  if (maxi == 0) {
    cout << 0;
    return 0;
  }
  cout << maxi << endl;
  for (int i = c[point1]; i <= point1; i++) {
    cout << s[i];
  }
  return 0;
}
