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 PYTHON3):

Solution:
 
# from math import factorial as fac
from collections import defaultdict
# from copy import deepcopy
import sys, math
f = None
try:
	f = open('q1.input', 'r')
except IOError:
	f = sys.stdin
if 'xrange' in dir(__builtins__):
	range = xrange
# print(f.readline())
# sys.setrecursionlimit(3*10**6)

	
def print_case_iterable(case_num, iterable):
	print("Case #{}: {}".format(case_num," ".join(map(str,iterable))))

def print_case_number(case_num, iterable):
	print("Case #{}: {}".format(case_num,iterable))

def print_iterable(A):
	print (' '.join(A))

def read_int():
	return int(f.readline().strip())
def read_int_array():
	return [int(x) for x in f.readline().strip().split(" ")]
def rns():
	a =  [x for x in f.readline().split(" ")]
	return int(a[0]), a[1].strip()
def read_string():
	return list(f.readline().strip())
def ri():
	return int(f.readline().strip())
def ria():
	return [int(x) for x in f.readline().strip().split(" ")]
def rns():
	a =  [x for x in f.readline().split(" ")]
	return int(a[0]), a[1].strip()
def rs():
	return list(f.readline().strip())
def bi(x):
	return bin(x)[2:]





from collections import deque
import math
NUMBER = 10**9 + 7
# NUMBER = 998244353
def factorial(n) : 
	M = NUMBER
	f = 1
  
	for i in range(1, n + 1):  
		f = (f * i) % M # Now f never can  
						# exceed 10^9+7  
	return f
def mult(a,b):
	return (a * b) % NUMBER

def minus(a , b):
	return (a - b) % NUMBER

def plus(a , b):
	return (a + b) % NUMBER

def egcd(a, b):
	if a == 0:
		return (b, 0, 1)
	else:
		g, y, x = egcd(b % a, a)
		return (g, x - (b // a) * y, y)

def modinv(a):
	m = NUMBER
	g, x, y = egcd(a, m)
	if g != 1:
		raise Exception('modular inverse does not exist')
	else:
		return x % m
def choose(n,k):
	if n < k:
		assert false
	return  mult(factorial(n), modinv(mult(factorial(k),factorial(n-k)))) % NUMBER
from collections import deque, defaultdict 
import heapq


from types import GeneratorType
def bootstrap(f, stack=[]):
	def wrappedfunc(*args, **kwargs):
		if stack:
			return f(*args, **kwargs)
		else:
			to = f(*args, **kwargs)
			while True:
				if type(to) is GeneratorType:
					stack.append(to)
					to = next(to)
				else:
					stack.pop()
					if not stack:
						break
					to = stack[-1].send(to)
			return to

	return wrappedfunc


def dfs(g, timeIn, timeOut,depths,parents): 
	# assign In-time to node u 
	cnt = 0
	# node, neig_i, parent, depth
	stack = [[1,0,0,0]]
	while stack:
		v,neig_i,parent,depth = stack[-1]
		parents[v] = parent
		depths[v] = depth
		# print (v)
		if neig_i == 0:
			timeIn[v] = cnt    
			cnt+=1
		while neig_i < len(g[v]):
			u = g[v][neig_i]
			if u == parent:
				neig_i+=1
				continue
			stack[-1][1] = neig_i + 1
			stack.append([u,0,v,depth+1])
			break
		if neig_i == len(g[v]):
			stack.pop()
			timeOut[v] = cnt
			cnt += 1
  
# def isAncestor(u: int, v: int, timeIn: list, timeOut: list) -> str: 
# 	return timeIn[u] <= timeIn[v] and timeOut[v] <= timeOut[u] 

cnt = 0
@bootstrap
def dfs(v,adj,timeIn, timeOut,depths,parents,parent=0,depth=0):
	global cnt
	parents[v] = parent
	depths[v] = depth
	timeIn[v] = cnt
	cnt+=1
	for u in adj[v]:
		if u == parent:
			continue
		yield dfs(u,adj,timeIn,timeOut,depths,parents,v,depth+1)
	timeOut[v] = cnt
	cnt+=1
	yield 

def gcd(a,b): 
	if a == 0: 
		return b 
	return gcd(b % a, a) 
  
# Function to return LCM of two numbers 
def lcm(a,b): 
	return (a*b) / gcd(a,b) 
def get_num_2_5(n):
	twos = 0
	fives = 0
	while n>0 and n%2 == 0:
		n//=2
		twos+=1
	while n>0 and n%5 == 0:
		n//=5
		fives+=1
	return (twos,fives)
def shift(a,i,num):
	for _ in range(num):
		a[i],a[i+1],a[i+2] = a[i+2],a[i],a[i+1]

def equal(x,y):
	return abs(x-y) <= 1e-9
# def leq(x,y):
# 	return x-y <= 1e-9
def getAngle(a, b, c):
	ang = math.degrees(math.atan2(c[1]-b[1], c[0]-b[0]) - math.atan2(a[1]-b[1], a[0]-b[0]))
	return ang + 360 if ang < 0 else ang
def getLength(a,b):
	return math.sqrt((a[0]-b[0])**2 + (a[1]-b[1])**2)


from heapq import heapify, heappush, heappop

def bfs(adj):
	s = set()
	d = defaultdict(set)
	# print('\n'.join(map(str,E.items())))
	q = deque([])
	s.add(0)
	d[0].add(0)
	q.append((0,0))
	while len(q) > 0:
		v,depth = q.popleft()
		for u in adj[v]:
			if u not in s:
				s.add(u)
				d[depth+1].add(u)
				q.append((u,depth+1))
		# print(q)
	return d



def isSubsetSum(arr, n, summ): 
	  
	# The value of subarr[i][j] will be  
	# true if there is a 
	# subarr of arr[0..j-1] with summ equal to i 
	subarr =([[False for i in range(summ + 1)]  
			for i in range(n + 1)]) 
	  
	# If summ is 0, then answer is true  
	for i in range(n + 1): 
		subarr[i][0] = True
		  
	# If summ is not 0 and arr is empty,  
	# then answer is false  
	for i in range(1, summ + 1): 
		 subarr[0][i]= False
			  
	# Fill the subarr table in botton up manner 
	for i in range(1, n + 1): 
		for j in range(1, summ + 1): 
			if j<arr[i-1]: 
				subarr[i][j] = subarr[i-1][j] 
			if j>= arr[i-1]: 
				subarr[i][j] = (subarr[i-1][j] or 
								subarr[i - 1][j-arr[i-1]]) 
	  
	# uncomment this code to print table  
	# for i in range(n + 1): 
	# for j in range(summ + 1): 
	# print (subset[i][j], end =" ") 
	# print() 
	return subarr[n][summ] 



def bfs(v,adj,onpath):
	# d is a dict for depth
	s = set()
	d = defaultdict(set)
	q = deque([])
	s.add(0)
	d[0].add(0)
	q.append((0,0))
	while len(q) > 0:
		v,depth = q.popleft()
		for u in adj[v]:
			if u not in s:
				s.add(u)
				d[depth+1].add(u)
				q.append((u,depth+1))
		# print(q)
	return d












def solution(s,n):
	zero = set()
	one = set()
	cnt = 1
	set_nums = [0 for i in range(n)]
	for i,x in enumerate(s):
		if x == '0':
			if len(one) > 0:
				set_num = one.pop()
				set_nums[i] = set_num
				zero.add(set_num)
			else:
				zero.add(cnt)
				set_nums[i] = cnt
				cnt+=1
		if x == '1':
			if len(zero) > 0:
				set_num = zero.pop()
				set_nums[i] = set_num
				one.add(set_num)
			else:
				one.add(cnt)
				set_nums[i] = cnt
				cnt+=1
	return f'{cnt-1}\n' + ' '.join(map(str,set_nums))
	# print(set_nums)				
	# return f'{cnt-1}'






def main():
	T = 1
	T = ri()
	for i in range(T):
		n = ri()
		s = rs()
		# a = ria()
		# n,m= ria()
		# q = []
		# for i in range(m):
		# 	q.append(ria())

		# a = ria()
		# s = rs()

		# adj = [list() for _ in range(n)]
		# for j in range(m):
		# 	a,b = ria()
		# 	a-=1;b-=1
		# 	adj[a].append(b)

		x = solution(s,n)

		# continue
		if 'xrange' not in dir(__builtins__):
			print(x) # print("Case #"+str(i+1)+':',x)
		else:
			print >>output,str(x)
	if 'xrange' in dir(__builtins__):
		print(output.getvalue())
		output.close()

if 'xrange' in dir(__builtins__):
	import cStringIO
	output = cStringIO.StringIO()
#example usage:
#    for l in res:
#       print >>output, str(len(l)) + ' ' +  ' '.join(l)

if __name__ == '__main__':
	main()