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.*;
import java.util.*;
import java.math.*;
import java.lang.*;

public class Cf131 implements Runnable 
{
    static class InputReader 
    {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private SpaceCharFilter filter;
        private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        public InputReader(InputStream stream) 
        {
            this.stream = stream;
        }
        
        public int read()
        {
            if (numChars==-1) 
                throw new InputMismatchException();
            
            if (curChar >= numChars) 
            {
                curChar = 0;
                try
                {
                    numChars = stream.read(buf);
                }
                catch (IOException e)
                {
                    throw new InputMismatchException();
                }
                
                if(numChars <= 0)               
                    return -1;
            }
            return buf[curChar++];
        }
    
        public String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }    
            return str;
        }
        public int nextInt() 
        {
            int c = read();
            
            while(isSpaceChar(c)) 
                c = read();
        
            int sgn = 1;
        
            if (c == '-') 
            {
                sgn = -1;
                c = read();
            }
            
            int res = 0;
            do
            {
                if(c<'0'||c>'9') 
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c)); 
        
            return res * sgn;
        }
        
        public long nextLong() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            long res = 0;
            
            do 
            {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }    
            while (!isSpaceChar(c));
                return res * sgn;
        }
        
        public double nextDouble() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-')
            {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') 
            {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') 
            {
                c = read();
                double m = 1;
                while (!isSpaceChar(c))
                {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
    
        public String readString() 
        {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do 
            {
                res.appendCodePoint(c);
                c = read();
            } 
            while (!isSpaceChar(c));
            
            return res.toString();
        }
    
        public boolean isSpaceChar(int c) 
        {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
    
        public String next()
        {
            return readString();
        }
        
        public interface SpaceCharFilter
        {
            public boolean isSpaceChar(int ch);
        }
    }
    public static void main(String args[]) throws Exception 
    {
        new Thread(null, new Cf131(),"Main",1<<27).start();
    }
    
    static class Pair{
        int nod;
        int ucn;
        
        
        Pair(int nod,int ucn){
            this.nod=nod;
            this.ucn=ucn;
            
        }
        
        public static Comparator<Pair> wc = new Comparator<Pair>(){
            public int compare(Pair e1,Pair e2){
                
                //reverse order
                if(e1.ucn < e2.ucn) 
                    return 1;  // 1 for swaping.
                else if (e1.ucn > e2.ucn) 
                    return -1; 
                else{
                    // if(e1.siz>e2.siz)
                    //     return 1;
                    // else
                    //     return -1;
                    return 0;
                } 
            }
        };	
    }

    public static long gcd(long a,long b){
        if(b==0)return a;
        else return gcd(b,a%b);
    }


    ////recursive BFS
    public static int bfsr(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,int[] pre){
        b[s]=true;
        int p = 0;
        int t = a[s].size();
        for(int i=0;i<t;i++){
            int x = a[s].get(i);
            if(!b[x]){
                dist[x] = dist[s] + 1;
                p+= (bfsr(x,a,dist,b,pre)+1);
            }
        }
        pre[s] = p;
        return p;
    }

//// iterative BFS
    public static int bfs(int s,ArrayList<Integer>[] a,int[] dist,boolean[] b,PrintWriter w){
        b[s]=true;
        int siz = 0;
        
        Queue<Integer> q = new LinkedList<>();
        q.add(s);
        while(q.size()!=0){
            int i=q.poll();
            Iterator<Integer> it = a[i].listIterator();
            int z=0;
            while(it.hasNext()){
                z=it.next();
                if(!b[z]){
                    b[z]=true;
                    dist[z] = dist[i] + 1;
                    siz++;
                    q.add(z);
                }
            }   
        
        }
        return siz;
    }

    


//////////////////////////////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////////////////////////////


    public void run()
    {
        InputReader sc = new InputReader(System.in);
        PrintWriter w = new PrintWriter(System.out);
        int defaultValue=0;
        

        int t = sc.nextInt();

        while(t-->0){
            int n = sc.nextInt();
            char[] a = sc.next().toCharArray();
            int[] aa = new int[n];
            int ans = 0;
            
            LinkedList<Integer>[] as = new LinkedList[2];
            as[0] = new LinkedList<Integer>();
            as[1] = new LinkedList<Integer>();

            for(int i=0;i<n;i++){
                int x = a[i]-'0';
                
                if(as[(x+1)%2].size()>0){
                    int y = as[(x+1)%2].poll();
                    aa[i] = y;
                    as[x].add(y);
                }
                else{
                    ans++;
                    as[x].add(ans);
                    aa[i] = ans;
                }
            }
            w.println(ans);
            for(int i=0;i<n;i++){
                w.print(aa[i]+ " ");
            }
            w.println("");
            
            


            
            
            

        }
        w.flush();
        w.close();
    }

}