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.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskA solver = new TaskA();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskA {
        public void solve(int testNumber, InputReader in, PrintWriter out) {
            String s = in.next();
            int[] subs = new int[s.length() + 1];
            for (int i = 1; i < s.length(); i++) {
                if ((s.charAt(i - 1) == '(' && s.charAt(i) == ')') || (s.charAt(i - 1) == '[' && s.charAt(i) == ']')) {
                    subs[i] = 2;
                }
            }
            for (int i = 1; i < s.length(); i++) {
                if (s.charAt(i) == ')' || s.charAt(i) == ']' && subs[i - 1] > 0) {
                    if (i - subs[i - 1] > 0) {
                        if ((s.charAt(i) == ')' && s.charAt(i - subs[i - 1] - 1) == '(') || (s.charAt(i) == ']' && s.charAt(i - subs[i - 1] - 1) == '[')) {
                            subs[i] = subs[i - 1] + 2;
                        }
                    }
                }
                if (subs[i] > 0 && i - subs[i] >= 0) {
                    subs[i] += subs[i - subs[i]];
                }
            }
            int ans = 0;
            int left = 0;
            int right = 0;
            for (int i = 1; i < subs.length; i++) {
                if (subs[i - 1] > subs[i]) {
                    int count = 0;
                    for (int j = i - subs[i - 1]; j < i; j++) {
                        if (s.charAt(j) == '[') count++;
                    }
                    if (count > ans) {
                        ans = count;
                        left = i - subs[i - 1];
                        right = i;
                    }
                }
            }
            out.println(ans);
            out.println(s.substring(left, right));
        }

    }

    static class InputReader {
        private StringTokenizer tokenizer;
        private BufferedReader reader;

        public InputReader(InputStream inputStream) {
            reader = new BufferedReader(new InputStreamReader(inputStream));
        }

        private void fillTokenizer() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
            }
        }

        public String next() {
            fillTokenizer();
            return tokenizer.nextToken();
        }

    }
}

