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.util.*;
import java.io.*;

public class A {
	public static void main(String[] args) throws IOException {
		setIO();

		int T = ni();
		while (T-- > 0) {
			int N = ni();
			char[] s = rl().toCharArray();
			
			Queue<Integer> zero = new LinkedList<>(), one = new LinkedList<>();
			
			int M = 0;
			
			int[] ans = new int[N];
			for (int i = 0; i < N; i++) {
				int k;
				if (s[i] == '0') {
					k = one.isEmpty() ? ++M : one.poll();
					zero.add(k);
				} else {
					k = zero.isEmpty() ? ++M : zero.poll();
					one.add(k);
				}
				ans[i] = k;
			}
			
			out.println(M);
			for (int k : ans) out.print(k + " ");
			out.println();
		}
		
		f.close();
		out.close();
	}

	static BufferedReader f;
	static PrintWriter out;
	static StringTokenizer st;

	static String rl() throws IOException {
		return f.readLine();
	}

	static int ni(StringTokenizer st) {
		return Integer.parseInt(st.nextToken());
	}

	static long nlg(StringTokenizer st) {
		return Long.parseLong(st.nextToken());
	}

	static int ni() throws IOException {
		return Integer.parseInt(rl());
	}

	static long nlg() throws IOException {
		return Long.parseLong(rl());
	}

	static StringTokenizer nl() throws IOException {
		return new StringTokenizer(rl());
	}

	static int[] nia(int N) throws IOException {
		StringTokenizer st = nl();
		int[] A = new int[N];
		for (int i = 0; i < N; i++)
			A[i] = ni(st);
		return A;
	}

	static void setIn(String s) throws IOException {
		f = new BufferedReader(new FileReader(s));
	}

	static void setOut(String s) throws IOException {
		out = new PrintWriter(new FileWriter(s));
	}

	static void setIn() {
		f = new BufferedReader(new InputStreamReader(System.in));
	}

	static void setOut() {
		out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));
	}

	static void setIO(String s) throws IOException {
		setIn(s + ".in");
		setOut(s + ".out");
	}

	static void setIO() {
		setIn();
		setOut();
	}
}