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.*;
import java.util.LinkedList;
import java.util.Queue;
import static java.lang.Math.*;

public class Cf294 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[] nextArray(int n)
		{
			int arr[] = new int[n];
			int i;
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
			}
			return arr;
		}
		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 int[] nextIntArray(int n)
		{
			int i;
			int arr[] = new int[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
			}
			return arr;
		}
		
		public long[] nextLongArray(int n)
		{
			int i;
			long arr[] = new long[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextLong();
			}
			return arr;
		}
		
		public double[] nextDoubleArray(int n)
		{
			int i;
			double arr[] = new double[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextDouble();
			}
			return arr;
		}
		
		public Integer[] IntegerArray(int n)
		{
			int i;
			Integer arr[] = new Integer[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextInt();
			}
			return arr;
		}
		
		public Long[] LongArray(int n)
		{
			int i;
			Long arr[] = new Long[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextLong();
			}
			return arr;
		}
		
		public Double[] DoubleArray(int n)
		{
			int i;
			Double arr[] = new Double[n];
			for(i=0;i<n;i++)
			{
				arr[i] = nextDouble();
			}
			return arr;
		}
		
		public ArrayList<ArrayList<Integer>> getGraph(int n,int m)
		{
			ArrayList<ArrayList<Integer>> g =new ArrayList<>();
			int i;
			for(i=0;i<=n;i++)
			{
				g.add(new ArrayList<>());
			}
			for(i=0;i<m;i++)
			{
				int x = nextInt();
				int y = nextInt();
				g.get(x).add(y);
				g.get(y).add(x);
			}
			return g;
		}
		
		public ArrayList<ArrayList<Integer>> getTree(int n)
		{
			ArrayList<ArrayList<Integer>> g =new ArrayList<>();
			int i;
			for(i=0;i<=n;i++)
			{
				g.add(new ArrayList<>());
			}
			for(i=0;i<n-1;i++)
			{
				int x = nextInt();
				int y = nextInt();
				g.get(x).add(y);
				g.get(y).add(x);
			}
			return g;
		}
	}
	
	public static int maxInt(int arr[])
	{
		int max = Integer.MIN_VALUE;
		for(int i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static int minInt(int arr[])
	{
		int min = Integer.MAX_VALUE;
		for(int i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	public static long maxLong(long arr[])
	{
		long max = Long.MIN_VALUE;
		for(long i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static long minLong(long arr[])
	{
		long min = Long.MAX_VALUE;
		for(long i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	public static double maxDouble(double arr[])
	{
		double max = Double.MIN_VALUE;
		for(double i : arr)
		{
			max = Math.max(i,max);
		}
		return max;
	}
	
	public static double minDouble(double arr[])
	{
		double min = Double.MAX_VALUE;
		for(double i : arr)
		{
			min = Math.min(i,min);
		}
		return min;
	}
	
	void merge(int arr[], int l, int m, int r) 
	{ 
		int n1 = m - l + 1; 
		int n2 = r - m; 
	  

		int L[] = new int [n1]; 
		int R[] = new int [n2]; 
	  

		for (int i=0; i<n1; ++i) 
		    L[i] = arr[l + i]; 
		for (int j=0; j<n2; ++j) 
		    R[j] = arr[m + 1+ j]; 
  
  
  

		int i = 0, j = 0; 
	  

		int k = l; 
		while (i < n1 && j < n2) 
		{ 
		    if (L[i] <= R[j]) 
		    { 
			arr[k] = L[i]; 
			i++; 
		    } 
		    else
		    { 
			arr[k] = R[j]; 
			j++; 
		    } 
		    k++; 
		} 

		while (i < n1) 
		{ 
		    arr[k] = L[i]; 
		    i++; 
		    k++; 
		} 
	  
   
		while (j < n2) 
		{ 
		    arr[k] = R[j]; 
		    j++; 
		    k++; 
		} 
	} 
  
    
	void sort(int arr[], int l, int r) 
	{ 
		if (l < r) 
		{ 
			int m = (l+r)/2; 
			sort(arr, l, m); 
			sort(arr , m+1, r); 
			merge(arr, l, m, r); 
		} 
	}
	
	static class Pair
	{
		int x,y;
		public Pair(int x,int y)
		{
			this.x = x;
			this.y = y;
		}
		public static Comparator<Pair> sortX = new Comparator<Pair>(){
			public int compare(Pair p1,Pair p2)
			{
				if(p1.x==p2.x)
				{
					return (int)(p1.y-p2.y);
				}
				return (int)(p1.x-p2.x);
			}
		};
		
		public static Comparator<Pair> sortY = new Comparator<Pair>(){
			public int compare(Pair p1,Pair p2)
			{
				if(p1.y==p2.y)
				{
					return (int)(p1.x-p2.x);
				}
				return (int)(p1.y-p2.y);
			}
		};
		
		public static Comparator<Pair> custom = new Comparator<Pair>(){
			public int compare(Pair p1,Pair p2)
			{
				if((p1.y-p1.x==p2.y-p2.x))
					return (int)(p1.x-p2.x);
				return (int)((p2.y-p2.x)-(p1.y-p2.x));
			}
		};
		
		public boolean equals(Object obj) 
		{
			if (obj == null) return false;
			if (!(obj instanceof Pair))
				return false;
			return (this.x == ((Pair) obj).x && this.y == ((Pair)obj).y);
		}

		public int hashCode()
		{
			if(x<0 || y<0)
			{
				return (int)(-5*x+-32*y);
			}
			return (int)(5*(x+y));
		}
	}
	
	static class DPair
	{
		Pair s,d;
		public DPair(Pair s,Pair d)
		{
			this.s = s;
			this.d = d;
		}
		
		public boolean equals(Object obj) 
		{
			if (obj == null) return false;
			if (!(obj instanceof DPair))
				return false;
			return (this.s.x == ((DPair) obj).s.x && this.s.y == ((DPair) obj).s.y && this.d.x == ((DPair)obj).d.x && this.d.y == ((DPair) obj).d.y);
		}
		public int hashCode()
		{
			return 5*(s.x+s.y+d.x+d.y);
		}
	}
	
	static class DSU
	{
		public static int rank[],parent[];
		int n;
		HashMap<Integer,Integer> map = new HashMap<>();
		
		public DSU(int n)
		{
			rank = new int[n+1];
			parent = new int[n+1];
			this.n = n;
			makeSet(n);
		}
		
		public void makeSet(int n)
		{
			for(int i=1;i<=n;i++)
			{
				parent[i] = i;
				map.put(i,1);
			}
		}
		
		public static int find(int x)
		{
			if(parent[x]!=x)
			{
				parent[x] = find(parent[x]);
			}
			return parent[x];
		}
		
		public void union(int x,int y)
		{
			int xRoot = find(x);
			int yRoot = find(y);
			
			if(xRoot==yRoot)
			{
				return;
			}
			
			if(rank[xRoot] < rank[yRoot])
			{
				parent[xRoot] = yRoot;
				rank[yRoot] = rank[xRoot] + 1;
				map.put(yRoot,map.getOrDefault(yRoot,1)+map.getOrDefault(xRoot,1));
				if(map.getOrDefault(xRoot,0)!=0)
				{
					map.remove(xRoot);
				}
			}
			else if(rank[yRoot] < rank[xRoot])
			{
				parent[yRoot] = xRoot;
				rank[xRoot] = rank[yRoot] + 1;
				map.put(xRoot,map.getOrDefault(xRoot,1) + map.getOrDefault(yRoot,1));
				if(map.getOrDefault(yRoot,0)!=0)
				{
					map.remove(yRoot);
				}
			}
			else
			{
				parent[yRoot] = xRoot;
				rank[xRoot] = rank[yRoot] + 1;
				map.put(xRoot,map.getOrDefault(xRoot,1)+map.getOrDefault(yRoot,1));
				if(map.getOrDefault(yRoot,0)!=0)
				{
					map.remove(yRoot);
				}
			}
		}
	}
	
	static class SegmentTree
	{
		public static int tree[];
		public SegmentTree(int arr[], int n) 
		{
			int x = (int) (Math.ceil(Math.log(n) / Math.log(2))); 
			int size = 2 * (int) Math.pow(2, x) - 1; 
			tree = new int[size];
			constructMinTree(arr, 0, n - 1, 0);
		}
		
		public int getMid(int s, int e) 
		{ 
			return s + (e - s) / 2; 
		} 
		
		public int minVal(int x, int y) 
		{ 
			return (x < y) ? x : y; 
		} 
		
		public int constructTree(int arr[], int s, int e, int ind) 
		{ 
			if (s == e) 
			{ 
				tree[ind] = arr[s]; 
				return arr[s]; 
			} 
			int mid = getMid(s, e); 
			tree[ind] = constructTree(arr, s, mid, ind * 2 + 1) +  constructTree(arr, mid + 1, e, ind * 2 + 2); 
			return tree[ind]; 
		}
		
		public long getSum(int n, int l, int r) 
		{ 
			if (l < 0 || r > n - 1 || l > r) 
			{				
				return -1; 
			} 
			return getSumR(0, n - 1, l, r, 0); 
		}
		
		public long getSumR(int s, int e, int l, int r, int ind) 
		{ 
			if (l <= s && r >= e)
			{
				return tree[ind]; 
			}
			if (e < l || s > r) 
			{
				return 0; 
			}
			int mid = getMid(s, e); 
			return getSumR(s, mid, l, r, 2 * ind + 1) + getSumR(mid + 1, e, l, r, 2 * ind + 2); 
		} 
		
		public  void updateValue(int arr[], int n, int i, int val) 
		{ 
			if (i < 0 || i > n - 1) 
			{ 
				return; 
			} 
			int diff = val - arr[i]; 
			arr[i] = val; 
			updateValueR(0, n - 1, i, diff, 0); 
		} 
		
		public void updateValueR(int s, int e, int i, int diff, int ind) 
		{ 
			if (i < s || i > e) 
			{
				return; 
			}
			tree[ind] = tree[ind] + diff; 
			if (e != s) 
			{ 
				int mid = getMid(s, e); 
				updateValueR(s, mid, i, diff, 2 * ind + 1); 
				updateValueR(mid + 1, e, i, diff, 2 * ind + 2); 
			} 
		}
		
		////FOR MIN APLLICATION
		public int constructMinTree(int arr[], int s, int e, int ind) 
		{ 
			if (s == e) 
			{ 
				tree[ind] = arr[s]; 
				return arr[s]; 
			} 
			int mid = getMid(s, e); 
			tree[ind] = minVal(constructMinTree(arr, s, mid, ind * 2 + 1), constructMinTree(arr, mid + 1, e, ind * 2 + 2)); 
			return tree[ind]; 
		} 
		
		
		public int getMin(int n,int l,int r)
		{
			if (l < 0 || r > n - 1 || l > r) 
			{				
				return -1; 
			} 
			return getMinR(0, n - 1, l, r, 0); 
		}
	
		public void updateValueMin(int arr[],int s, int e, int index, int value, int node) 
		{ 
			if (index < s || index > e) 
			{ 
				return; 
			} 
			if (s == e) 
			{  
				arr[index] = value; 
				tree[node] = value; 
			}  
			else
			{ 
				int mid = getMid(s, e); 
				if (index >= s && index <= mid)
				{					
					updateValueMin(arr,s, mid, index, value, 2 * node + 1); 
				}
				else
				{
					updateValueMin(arr,mid + 1, e, index, value, 2 * node + 2);   
				}
				tree[node] = Math.min(tree[2 * node + 1], tree[2 * node + 2]); 
			} 
			return; 
		} 
	
		public int getMinR(int s, int e, int l, int r, int index) 
		{ 
			if (l <= s && r >= e) 
			{
				return tree[index]; 
			}
			if (e < l || s > r) 
			{
				return Integer.MAX_VALUE; 
			}
			int mid = getMid(s, e); 
			return minVal(getMinR(s, mid, l, r, 2 * index + 1) , getMinR(mid + 1, e, l, r, 2 * index + 2));
		}
	}
	
	public static void main(String args[]) throws Exception 
	{
		new Thread(null, new Cf294(),"Main",1<<27).start();
	}	
	
	
	public void run()	
	{
		InputReader in = new InputReader(System.in);
		PrintWriter w = new PrintWriter(System.out);
		int TESTCASES = in.nextInt();
		while(TESTCASES-->0)
		{
			int n = in.nextInt();
			String s = new String();
			s = in.next();
			ArrayList<Integer> res = new ArrayList<>();
			Stack<Integer> z = new Stack<>();
			Stack<Integer> o = new Stack<>();
			int i,j,k;
			int count = 0;
			for(i=0;i<n;i++)
			{
				if(s.charAt(i)=='0')
				{
					if(!o.empty())
					{
						z.push(o.pop());
						res.add(z.peek());
					}
					else
					{
						res.add(count+1);
						z.push(count+1);
						count+=1;
					}
				}
				else
				{
					if(!z.empty())
					{
						o.push(z.pop());
						res.add(o.peek());
					}
					else
					{
						res.add(count+1);
						o.push(count+1);
						count+=1;
					}
				}
			}
			w.println(count);
			for(Integer x : res)
			{
			    w.print(x + " ");
			}
			w.println();
		}
		w.flush();
		w.close();
	}
}