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
import java.awt.geom.*;
import java.io.*;
import java.math.*;
import java.util.*;
import java.util.regex.*;
import static java.lang.Math.*;
public class A {

    static class T {
        char ch;
        int index;
        public T(char _ch, int _index) {
            ch = _ch;
            index = _index;
        }
    }

    public A() throws Exception {
        char[] s = br.readLine().toCharArray();
        char[] invert = new char[128];
        invert[']'] = '[';
        invert[')'] = '(';
        Stack<Character> chStack = new Stack<Character>();
        Stack<Integer> posStack = new Stack<Integer>();
        boolean[] set = new boolean[s.length];
        for (int i=0; i<s.length; i++) {
            switch (s[i]) {
                case '[':
                case '(':
                    chStack.push(s[i]);
                    posStack.push(i);
                    break;
                case ']':
                case ')':
                    if (chStack.empty()) continue;
                    if (chStack.peek()!=invert[s[i]]) {
                        chStack.clear();
                        posStack.clear();
                    } else {
                        chStack.pop();
                        set[posStack.pop()] = true;
                        set[i] = true;
                    }
                    break;
            }
        }

        int best = 0;
        int p = 0;
        int len = 0;

        for (int i=0; i<s.length; i++) {
            int cnt = 0;
            int j = i;
            for (; j<s.length; j++) {
                if (!set[j]) break;
                if (s[j]=='[') cnt++;
            }
            if (best<cnt) {
                best = cnt;
                p = i;
                len = j-i;
            }
            i = j;
        }

        System.out.println(best);
        System.out.println(new String(s, p, len));
    }

    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringBuilder buf = new StringBuilder();
    public static void main(String[] args) throws Exception { // {{{
        new A();
    } // }}}
    public static void debug(Object... arr) { // {{{
        System.err.println(Arrays.deepToString(arr));
    } // }}}
}
