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 functools import reduce
import os
import sys
from collections import *
#from fractions import *
from math import *
from bisect import *
from heapq import *
from io import BytesIO, IOBase
input = lambda: sys.stdin.readline().rstrip("\r\n")
def value(): return tuple(map(int, input().split())) # multiple values
def arr(): return [int(i) for i in input().split()] # array input
def sarr(): return [int(i) for i in input()] #array from string
def starr(): return [str(x) for x in input().split()] #string array
def inn(): return int(input()) # integer input
def svalue(): return tuple(map(str, input().split())) #multiple string values
def parr(): return [(value()) for i in range(n)] # array of pairs
mo = 1000000007
inf=1e18
div=998244353
# ----------------------------CODE------------------------------#
for _ in range(inn()):
    n=inn()
    a=[int(x) for x in input()]
    ans=[]
    val=0
    d=defaultdict(list)
    for i in range(n):
        res=a[i]^1
        if(len(d[res])==0):
            val+=1
            ans+=[val]
            d[a[i]]+=[val]
        else:
            sub=d[res][len(d[res])-1]
            ans+=[sub]
            d[a[i]]+=[sub]
            d[res].pop()
        #print(d)
    print(max(ans))
    for i in range(n):
        print(ans[i],end=" ")
    print()