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.*;
/* * */

public class _661C implements Runnable{
    public static void main(String[] args) {
	    new Thread(null, new _661C(),"Main",1<<27).start();
    }
    @Override
    public void run() {
        FastReader fd = new FastReader(System.in);
        PrintWriter out = new PrintWriter(System.out);
        int t = fd.nextInt();
        for(int te = 0; te < t; te++){
            int n = fd.nextInt();
            char[] d = fd.next().toCharArray();
            int cur = 0;
            int[] ans = new int[n];


            LinkedList<Integer> zeroZ = new LinkedList<>();
            LinkedList<Integer> zeroO = new LinkedList<>();

            for(int i = 0; i < n; i++){
                if(d[i] == '0'){
                    if(zeroZ.size() > 0) ans[i] = zeroZ.removeFirst();
                    else {ans[i] = cur; cur++;}
                    zeroO.add(ans[i]);
                }
                if(d[i] == '1'){
                    if(zeroO.size() > 0) ans[i] = zeroO.removeFirst();
                    else {ans[i] = cur; cur++;}
                    zeroZ.add(ans[i]);
                }
            }
            out.println(cur);
            for(int i : ans)out.print((i+1)+" ");
            out.println();
        }
        out.close();
    }

    private int getSequence(int cur, int[] ans, ArrayList<Integer> zeros, ArrayList<Integer> ones, LinkedList<Integer> zeroZ, LinkedList<Integer> zeroO, LinkedList<Integer> oneZ, LinkedList<Integer> oneO, int i) {
        if(zeros.size() > 0 && zeroZ.size() > 0){
            int group = zeros.get(zeroZ.removeFirst());
            ans[i] = group;
            zeroO.add(zeroO.size());
        }
        if(ans[i] == 0 && ones.size() > 0 && oneZ.size() > 0){
            int group = ones.get(oneZ.removeFirst());
            ans[i] = group;
            oneO.add(oneO.size());
        }
        if(ans[i] == 0){
            ones.add(cur);
            ans[i] = cur;
            oneO.add(ones.size()-1);
            cur++;
        }
        return cur;
    }

    //Helper functions
    static int[] getArray(int n,boolean isSorted, FastReader fd){
        int[] data = new int[n];
        for(int i = 0; i < data.length; i++){ data[i] = fd.nextInt(); }
        if(isSorted) Arrays.sort(data);
        return data;
    }
    static int gcd(int a, int b) {
        if (a == 0)
            return b;
        return gcd(b % a, a);
    }

    static int lcm(int a, int b) {
        return (a*b)/gcd(a, b);
    }


    static class FastReader {
        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 FastReader(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);
        }
    }
}