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.util.Arrays;
import java.util.Scanner;

public class Spider120F {

    /**
     * @param args the command line arguments
     */
    
    
    public static void main(String[] args) {
        // TODO code application logic here
        Scanner input=new Scanner(System.in);
        String s=input.next();
        int[] stack=new int[s.length()+10];
        Arrays.fill(stack,-1);
        boolean[] pair=new boolean[s.length()];
        int stackPointer=0;
        for(int i=0;i<s.length();i++){
            if(s.charAt(i)=='['||s.charAt(i)=='(')
                stack[stackPointer++]=i;
            else{ 
                 if(stackPointer > 0 && ((s.charAt(i) == ')' &&  s.charAt(stack[stackPointer - 1]) == '(') || (s.charAt(i) == ']' && s.charAt(stack[stackPointer - 1]) == '['))){
                    pair[i]=true;
                    pair[stack[stackPointer-1]]=true;
                    --stackPointer;
                }
                else
                    stackPointer=0;
            }
        }
        int left=0,maxBrace=0,len=0;
         for (int i = 0; i < s.length(); ++i) {
            if (pair[i] && (i == 0 || !pair[i - 1])) {
                int j;
                int numBrackets = 0;
                for (j = i; j < s.length(); ++j) {
                    if (!pair[j]) break;
                    if (s.charAt(j) == '[') ++numBrackets;
                }
                if (numBrackets > maxBrace) {
                    maxBrace = numBrackets;
                    left = i;
                    len = j - i;
                }
            }
        }
        System.out.println(maxBrace);
        System.out.println(s.substring(left, left + len));
    }
    }