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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
import java.util.Stack;

public class ProblemA {
    static char[] match = new char[512];
    static boolean[] flag;
    static String line;
    static int len;

    public static void main(String[] args) throws IOException {
        BufferedReader s = new BufferedReader(new InputStreamReader(System.in));
        line = s.readLine();
        len = line.length();
        flag = new boolean[len];
        match['('] = ')';
        match['['] = ']';
        
        Stack<Character> ps = new Stack<Character>();
        Stack<Integer> is = new Stack<Integer>();
        for (int i = 0 ; i < len ; i++) {
            char c1 = line.charAt(i);
            if (c1 == '[' || c1 == '(') {
                ps.add(c1);
                is.add(i);
            } else {
                if (ps.size() == 0 || match[ps.peek()] != c1) {
                    ps.clear();
                    is.clear();
                } else {
                    ps.pop();
                    int from = is.pop();
                    int to = i;
                    flag[from] = true;
                    flag[to] = true;
                }
            }
        }
        
        int maxcnt = 0;
        int maxfrom = 0;
        int maxto = 0;
        for (int i = 0 ; i < len ; ) {
            if (flag[i]) {
                int cnt = 0;
                int from = i;
                while (i < len && flag[i]) {
                    if (line.charAt(i) == '[') {
                        cnt++;
                    }
                    i++;
                }
                if (maxcnt < cnt) {
                    maxcnt = cnt;
                    maxfrom = from;
                    maxto = i;
                }
            } else {
                i++;
            }
        }
        System.out.println(maxcnt);
        System.out.println(line.substring(maxfrom, maxto));
    }

}