Problem: You are given a binary string s consisting of n zeros and ones.

Your task is to divide the given string into the minimum number of subsequences in such a way that each character of the string belongs to exactly one subsequence and each subsequence looks like "010101 ..." or "101010 ..." (i.e. the subsequence should not contain two adjacent zeros or ones).

Recall that a subsequence is a sequence that can be derived from the given sequence by deleting zero or more elements without changing the order of the remaining elements. For example, subsequences of "1011101" are "0", "1", "11111", "0111", "101", "1001", but not "000", "101010" and "11100".

You have to answer t independent test cases.

Input

The first line of the input contains one integer t (1 ≤ t ≤ 2 ⋅ 10^4) — the number of test cases. Then t test cases follow.

The first line of the test case contains one integer n (1 ≤ n ≤ 2 ⋅ 10^5) — the length of s. The second line of the test case contains n characters '0' and '1' — the string s.

It is guaranteed that the sum of n does not exceed 2 ⋅ 10^5 (∑ n ≤ 2 ⋅ 10^5).

Output

For each test case, print the answer: in the first line print one integer k (1 ≤ k ≤ n) — the minimum number of subsequences you can divide the string s to. In the second line print n integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ k), where a_i is the number of subsequence the i-th character of s belongs to.

If there are several answers, you can print any.

Example

Input


4
4
0011
6
111111
5
10101
8
01010000


Output


2
1 2 2 1 
6
1 2 3 4 5 6 
1
1 1 1 1 1 
4
1 1 1 1 1 2 3 4 

Solution (in JAVA):

Solution:
import java.io.BufferedReader;
import java.io.*;
import java.util.*;

public class d {

    static BufferedReader br;
    static long mod = 1000000000 + 7;
    static HashSet<Integer> p = new HashSet<>();
     static boolean debug =true;
           //  Arrays.sort(time  , (a1,a2) -> (a1[0]-a2[0])); 2d array sort lamda
    public static void main(String[] args) throws Exception {
        br = new BufferedReader(new InputStreamReader(System.in));
        int tc = 1;
        tc = cinI();
      PrintWriter pr  =new PrintWriter(System.out);
        while (tc-- > 0) {


               int  n= cinI();
               char[] ar=cin().toCharArray();
               Stack<Integer> z = new Stack<>();
               Stack<Integer> o  = new Stack<>();

               int[] ans = new int[n];
 
               for(int i=0;i<n;i++){
               	if(ar[i]=='0'){
               		if(o.isEmpty()==true){
               			ans[i]=z.size()+1;
               			z.push(ans[i]);
               		}
               		else{
               			ans[i]=o.pop();
                          z.push(ans[i]);
               		}

               	}
               	else{
               		if(z.isEmpty()==true){
               			ans[i]=o.size()+1;
               			o.push(ans[i]);
               		}
               		else{
               			ans[i]=z.pop();
                          o.push(ans[i]);
               		}
               	}
               }
               //pr.println(max(o.size(),z.size()));
               int mx=1;
               for(int i=0;i<n;i++){
               	mx=max(mx,ans[i]);
               	//pr.print(ans[i]+" ");
               }
               pr.println(mx);
               for(int i=0;i<n;i++){
               	//mx=max(mx,ans[i]);
               	pr.print(ans[i]+" ");
               }
               pr.println();
        }
        pr.close();
    }

    public static <E> void print(String var ,E e){
      if(debug==true){
      System.out.println(var +" "+e);
      }
    }
     private static long[]  sort(long[] e){
     ArrayList<Long> x=new ArrayList<>();
     for(long c:e){
       x.add(c);
     }
     Collections.sort(x);
     long[] y = new long[e.length];
     for(int i=0;i<x.size();i++){
       y[i]=x.get(i);
     }
     return y;
     }
    public static void printDp(long[][] dp) {

        int n = dp.length;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < dp[0].length; j++) {
                System.out.print(dp[i][j] + " ");
            }
            System.out.println();
        }
    }

    


  

    private static long gcd(long a, long b) {
        if (a == 0)
            return b;
        if (b == 0)
            return a;

        // base case
        if (a == b)
            return a;

        // a is greater
        if (a > b)
            return gcd(a % b, b);
        return gcd(a, b % a);
    }


    public static long min(long a, long b) {
        return Math.min(a, b);
    }

    public static int min(int a, int b) {
        return Math.min(a, b);
    }


    public static void sieve() {
        int[] pf = new int[100000000 + 1];
        //0 prime //1 not prime
        pf[0] = 1;
        pf[1] = 1;
        for (int j = 2; j <= 10000; j++) {

            if (pf[j] == 0) {
                p.add(j);
                for (int k = j * j; k < pf.length; k += j) {
                    pf[k] = 1;
                }
            }
        }

    }


    public static int[] readArray(int n, int x, int z) throws Exception {
        int[] arr = new int[n];
        String[] ar = cinA();
        for (int i = x; i < n + x; i++) {
            arr[i] = getI(ar[i - x]);
        }
        return arr;
    }

    public static long[] readArray(int n, int x) throws Exception {
        long[] arr = new long[n];
        String[] ar = cinA();
        for (int i = x; i < n + x; i++) {
            arr[i] = getL(ar[i - x]);
        }
        return arr;
    }

    public static void arrinit(String[] a, long[] b) throws Exception {
        for (int i = 0; i < a.length; i++) {
            b[i] = Long.parseLong(a[i]);
        }
    }

    public static HashSet<Integer>[] Graph(int n, int edge, int directed) throws Exception {
        HashSet<Integer>[] tree = new HashSet[n];

        for (int j = 0; j < edge; j++) {

            String[] uv = cinA();
            int u = getI(uv[0]);
            int v = getI(uv[1]);
            if (directed == 0) {

                tree[v].add(u);
            }
            tree[u].add(v);
        }
        return tree;
    }

    public static void arrinit(String[] a, int[] b) throws Exception {
        for (int i = 0; i < a.length; i++) {
            b[i] = Integer.parseInt(a[i]);
        }
    }


    static double findRoots(int a, int b, int c) {
        // If a is 0, then equation is not
        //quadratic, but linear


        int d = b * b - 4 * a * c;
        double sqrt_val = Math.sqrt(Math.abs(d));


        // System.out.println("Roots are real and different \n");

        return Math.max((double) (-b + sqrt_val) / (2 * a),
                (double) (-b - sqrt_val) / (2 * a));


    }

    public static String cin() throws Exception {
        return br.readLine();
    }

    public static String[] cinA() throws Exception {
        return br.readLine().split(" ");
    }

    public static String[] cinA(int x) throws Exception {
        return br.readLine().split("");
    }

    public static String ToString(Long x) {
        return Long.toBinaryString(x);
    }

    public static void cout(String s) {
        System.out.println(s);
    }

    public static Integer cinI() throws Exception {
        return Integer.parseInt(br.readLine());
    }

    public static int getI(String s) throws Exception {
        return Integer.parseInt(s);
    }

    public static long getL(String s) throws Exception {
        return Long.parseLong(s);
    }

    public static long max(long a, long b) {
        return Math.max(a, b);
    }

    public static int max(int a, int b) {
        return Math.max(a, b);
    }

    public static void coutI(int x) {
        System.out.println(String.valueOf(x));
    }

    public static void coutI(long x) {
        System.out.println(String.valueOf(x));
    }

    public static Long cinL() throws Exception {
        return Long.parseLong(br.readLine());
    }

    public static void arrInit(String[] arr, int[] arr1) throws Exception {
        for (int i = 0; i < arr.length; i++) {
            arr1[i] = getI(arr[i]);
        }

    }
}