Recently Chef learned about Longest Increasing Subsequence. To be precise, he means longest strictly increasing subsequence, when he talks of longest increasing subsequence.  To check his understanding, he took his favorite n-digit number and for each of its n digits, he computed the length of the longest increasing subsequence of digits ending with that digit. Then he stored these lengths in an array named LIS.
For example, let us say that Chef's favourite 4-digit number is 1531, then the LIS array would be [1, 2, 2, 1]. The length of longest increasing subsequence ending at first digit is 1 (the digit 1 itself) and at the second digit is 2 ([1, 5]), at third digit is also 2 ([1, 3]), and at the 4th digit is 1 (the digit 1 itself).
Now Chef wants to give you a challenge. He has a valid LIS array with him, and wants you to find any n-digit number having exactly the same LIS array? You are guaranteed that Chef's LIS array is valid, i.e. there exists at least one n-digit number corresponding to the given LIS array.

-----Input-----
The first line of the input contains an integer T denoting the number of test cases. 
For each test case, the first line contains an integer n denoting the number of digits in Chef's favourite number.
The second line will contain n space separated integers denoting LIS array, i.e. LIS1, LIS2, ..., LISn.

-----Output-----
For each test case, output a single n-digit number (without leading zeroes) having exactly the given LIS array. If there are multiple n-digit numbers satisfying this requirement, any of them will be accepted.

-----Constraints-----
- 1 ≤ T ≤ 30 000
- 1 ≤ n ≤ 9
- It is guaranteed that at least one n-digit number having the given LIS array exists

-----Example-----
Input:
5
1 
1
2 
1 2
2 
1 1
4
1 2 2 1
7 
1 2 2 1 3 2 4

Output:
7
36
54
1531
1730418

-----Explanation-----
Example case 1. All one-digit numbers have the same LIS array, so any answer from 0 to 9 will be accepted.
Example cases 2 & 3. For a two digit number we always have LIS1 = 1, but the value of LIS2 depends on whether the first digit is strictly less than the second one. If this is the case (like for number 36), LIS2 = 2, otherwise (like for numbers 54 or 77) the values of LIS2 is 1.
Example case 4. This has already been explained in the problem statement.
Example case 5. 7-digit number 1730418 has LIS array [1, 2, 2, 1, 3, 2, 4]:
indexLISlength117304181217304182317304182417304181517304183617304182717304184

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
m = int(input())
while m:
	m -= 1
	n = int(input())
	t = [i for i in input().split()]
	print(''.join(t))


def longest_subsequence(_list):
	return ''.join(map(str, _list))

def __starting_point():
	t = int(input())
	for _ in range(t):
		n = input()
		_list = list(map(int, input().split()))
		print(longest_subsequence(_list))
__starting_point()


for _ in range(int(input())):
	n = int(input())
	s = list(map(int, input().split()))
	s = ''.join(map(str, s))
	print(s)


from fractions import Fraction
import numpy as np
import sys, bisect, copyreg, statistics, os, time, socket, socketserver, atexit, io
from math import gcd, ceil, floor, sqrt, copysign, factorial, fmod, fsum, degrees
from math import expm1, exp, log, log2, acos, asin, cos, tan, sin, pi, e, tau, inf, nan, atan2
from collections import Counter, defaultdict, deque, OrderedDict
from itertools import combinations, permutations, accumulate, groupby, compress
from numpy.linalg import matrix_power as mp
from bisect import bisect_left, bisect_right, bisect, insort, insort_left, insort_right
from statistics import *
from copy import copy, deepcopy
from functools import reduce, cmp_to_key, lru_cache
from io import BytesIO, IOBase
from scipy.spatial import ConvexHull
from heapq import *
from decimal import *
from queue import Queue, PriorityQueue
from re import sub, subn
from random import shuffle, randrange, randint, random
from types import GeneratorType
from string import ascii_lowercase
from time import perf_counter
from datetime import datetime
from operator import ior
if sys.version_info[0] < 3:
	from builtins import xrange as range
	from future_builtins import ascii, filter, hex, map, oct, zip

def graph(vertex):
	return [[] for i in range(vertex + 1)]

def lcm(a, b):
	return a * b // gcd(a, b)

def most_frequent(List):
	return Counter(List).most_common(1)[0][0]

def most_common(List):
	return mode(List)

def chinese_remainder(a, p):
	prod = reduce(op.mul, p, 1)
	x = [prod // piii for piii in p]
	return sum((a[i] * pow(x[i], p[i] - 2, p[i]) * x[i] for i in range(len(a)))) % prod

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 readTree():
	v = II()
	adj = [set() for i in range(v + 1)]
	for i in range(v - 1):
		(u1, u2) = MI()
		adj[u1].add(u2)
		adj[u2].add(u1)
	return (adj, v)

def setBit(n):
	return bin(n).count('1')

def digitsSum(n):
	return sum(list(map(int, str(n).strip())))

def ncr(n, r):
	r = min(r, n - r)
	numer = reduce(op.mul, list(range(n, n - r, -1)), 1)
	denom = reduce(op.mul, list(range(1, r + 1)), 1)
	return numer // denom

def factors(n):
	return list(set(reduce(list.__add__, ([i, n // i] for i in range(1, int(n ** 0.5) + 1) if n % i == 0))))

def prime_factors(n):
	(i, factors) = (2, [])
	while i * i <= n:
		if n % i:
			i += 1
		else:
			n //= i
			factors.append(i)
	if n > 1:
		factors.append(n)
	return set(factors)

def prefixSum(arr):
	for i in range(1, len(arr)):
		arr[i] = arr[i] + arr[i - 1]
	return arr

def binomial_coefficient(n, k):
	if 0 <= k <= n:
		ntok = 1
		ktok = 1
		for t in range(1, min(k, n - k) + 1):
			ntok *= n
			ktok *= t
			n -= 1
		return ntok // ktok
	else:
		return 0

def get_num_2_5(n):
	fives = 0
	while n > 0 and n % 5 == 0:
		n //= 5
		fives += 1
	return (power2(n), 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 powerOfK(k, max):
	if k == 1:
		return [1]
	if k == -1:
		return [-1, 1]
	result = []
	n = 1
	while n <= max:
		result.append(n)
		n *= k
	return result

def getAngle(a, b, c):
	ang = degrees(atan2(c[1] - b[1], c[0] - b[0]) - atan2(a[1] - b[1], a[0] - b[0]))
	return ang + 360 if ang < 0 else ang

def getLength(a, b):
	return sqrt((a[0] - b[0]) ** 2 + (a[1] - b[1]) ** 2)

def kadane(a, size):
	max_so_far = curr_max = a[0]
	for i in range(1, size):
		curr_max = max(a[i], curr_max + a[i])
		max_so_far = max(max_so_far, curr_max)
	return max_so_far

def divisors(n):
	result = []
	for i in range(1, ceil(sqrt(n)) + 1):
		if n % i == 0:
			result.append(i)
			result.append(n / i)
	return list(set(result))

def equal(x, y):
	return abs(x - y) <= 1e-09

def sumtilln(n):
	return n * (n + 1) // 2

def isPrime(n):
	if n <= 1:
		return False
	if n <= 3:
		return True
	if n % 2 == 0 or n % 3 == 0:
		return False
	for i in range(5, ceil(sqrt(n)) + 1, 6):
		if n % i == 0 or n % (i + 2) == 0:
			return False
	return True

def isPowerOf2(x):
	return x and (not x & x - 1)

def power2(n):
	return len(str(bin(n & ~(n - 1))) - 1)

def sqsum(n):
	return n * (n + 1) * (2 * n + 1) // 6

def cusum(n):
	return sumn(n) ** 2

def pa(a):
	print(*a)

def printarrayasstring(a):
	print(*a, sep='')

def pm(a):
	for i in a:
		print(*i)

def pmasstring(a):
	for i in a:
		print(*i, sep='')

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 isPerfectSquare(n):
	return pow(floor(sqrt(n)), 2) == n

def nC2(n, m):
	return n * (n - 1) // 2 % m

def modInverse(n, p):
	return pow(n, p - 2, p)

def ncrmodp(n, r, p):
	num = den = 1
	for i in range(r):
		num = num * (n - i) % p
		den = den * (i + 1) % p
	return num * pow(den, p - 2, p) % p

def reverse(string):
	return ''.join(reversed(string))

def listtostr(s):
	return ' '.join([str(elem) for elem in s])

def binarySearch(arr, l, r, x):
	while l <= r:
		mid = l + (r - l) // 2
		if arr[mid] == x:
			return mid
		elif arr[mid] < x:
			l = mid + 1
		else:
			r = mid - 1
	return -1

def largestPower(n, p):
	x = 0
	while n:
		n //= p
		x += n
	return x

def isarrayodd(a):
	return len(a) == len(list(filter(lambda x: x % 2 == 1, a)))

def isarrayeven(a):
	return len(a) == len(list(filter(lambda x: x % 2 == 0, a)))

def isPalindrome(s):
	return s == s[::-1]

def gt(x, h, c, t):
	return (x * h + (x - 1) * c) / (2 * x - 1)

def CountFrequency(my_list):
	return Counter(my_list)

def CountFrequencyasPair(my_list1, my_list2, freq):
	for item in my_list1:
		freq[item][0] = freq[item][0] + 1 if item in freq else 1
	for item in my_list2:
		freq[item][1] = freq[item][1] + 1 if item in freq else 1
	return freq

def CountSquares(a, b):
	return floor(sqrt(b)) - ceil(sqrt(a)) + 1

def binarySearchCount(arr, n, key):
	left = 0
	right = n - 1
	count = 0
	while left <= right:
		mid = int((right + left) / 2)
		if arr[mid] <= key:
			(count, left) = (mid + 1, mid + 1)
		else:
			right = mid - 1
	return count

def primes(n):
	(sieve, l) = ([True] * (n + 1), [])
	for p in range(2, n + 1):
		if sieve[p]:
			l.append(p)
		for i in range(p, n + 1, p):
			sieve[i] = False
	return l

def Next_Greater_Element_for_all_in_array(arr):
	(s, n, reta, retb) = (list(), len(arr), [], [])
	arr1 = [list([0, i]) for i in range(n)]
	for i in range(n - 1, -1, -1):
		while len(s) > 0 and s[-1][0] <= arr[i]:
			s.pop()
		arr1[i][0] = -1 if len(s) == 0 else s[-1]
		s.append(list([arr[i], i]))
	for i in range(n):
		reta.append(list([arr[i], i]))
		retb.append(arr1[i][0])
	return (reta, retb)

def find_lcm_array(A):
	l = A[0]
	for i in range(1, len(A)):
		l = lcm(l, A[i])
	return l

def polygonArea(X, Y, n):
	area = 0.0
	j = n - 1
	for i in range(n):
		area += (X[j] + X[i]) * (Y[j] - Y[i])
		j = i
	return abs(area / 2.0)

def merge(a, b):
	return a | b

def subarrayBitwiseOR(A):
	(res, pre) = (set(), {0})
	for x in A:
		pre = {x | y for y in pre} | {x}
		res |= pre
	return len(res)

def subset_sum(numbers, l, target, partial=[]):
	s = sum(partial)
	if l <= s <= target:
		print('sum(%s)=%s' % (partial, s))
	if s >= target:
		return
	for i in range(len(numbers)):
		subset_sum(numbers[i + 1:], l, target, partial + [numbers[i]])

def isSubsetSum(arr, n, summ):
	subarr = [[False for i in range(summ + 1)] for i in range(n + 1)]
	for i in range(n + 1):
		subarr[i][0] = True
	for i in range(1, summ + 1):
		subarr[0][i] = False
	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]]
	return subarr[n][summ]

def pre(s):
	n = len(s)
	pi = [0] * n
	for i in range(1, n):
		j = pi[i - 1]
		while j and s[i] != s[j]:
			j = pi[j - 1]
		if s[i] == s[j]:
			j += 1
		pi[i] = j
	return pi

def prodofarray(a):
	return np.prod(a)

def binary(x, length=16):
	y = bin(x)[2:]
	return y if len(y) >= length else '0' * (length - len(y)) + y

def printSubsequences(arr, index, subarr):
	if index == len(arr):
		if len(subarr) != 0:
			print(subarr)
	else:
		printSubsequences(arr, index + 1, subarr)
		printSubsequences(arr, index + 1, subarr + [arr[index]])
	return

def modFact(n, p):
	if n >= p:
		return 0
	result = 1
	for i in range(1, n + 1):
		result = result * i % p
	return result

class LRUCache:

	def __init__(self, capacity: int):
		self.cache = OrderedDict()
		self.capacity = capacity

	def get(self, key: int) -> int:
		if key not in self.cache:
			return -1
		else:
			self.cache.move_to_end(key)
			return self.cache[key]

	def put(self, key: int, value: int) -> None:
		self.cache[key] = value
		self.cache.move_to_end(key)
		if len(self.cache) > self.capacity:
			self.cache.popitem(last=False)

class segtree:

	def __init__(self, n):
		self.m = 1
		while self.m < n:
			self.m *= 2
		self.data = [0] * (2 * self.m)

	def __setitem__(self, i, x):
		x = +(x != 1)
		i += self.m
		self.data[i] = x
		i >>= 1
		while i:
			self.data[i] = self.data[2 * i] + self.data[2 * i + 1]
			i >>= 1

	def __call__(self, l, r):
		l += self.m
		r += self.m
		s = 0
		while l < r:
			if l & 1:
				s += self.data[l]
				l += 1
			if r & 1:
				r -= 1
				s += self.data[r]
			l >>= 1
			r >>= 1
		return s

class FenwickTree:

	def __init__(self, n):
		self.n = n
		self.bit = [0] * (n + 1)

	def update(self, x, d):
		while x <= self.n:
			self.bit[x] += d
			x += x & -x

	def query(self, x):
		res = 0
		while x > 0:
			res += self.bit[x]
			x -= x & -x
		return res

	def range_query(self, l, r):
		return self.query(r) - self.query(l - 1)

class Graph:

	def __init__(self, V):
		self.V = V
		self.adj = [[] for i in range(V)]

	def DFSUtil(self, temp, v, visited):
		visited[v] = True
		temp.append(v)
		for i in self.adj[v]:
			if visited[i] == False:
				temp = self.DFSUtil(temp, i, visited)
		return temp

	def addEdge(self, v, w):
		self.adj[v].append(w)
		self.adj[w].append(v)

	def connectedComponents(self):
		(visited, cc) = ([False for i in range(self.V)], [])
		for v in range(self.V):
			if visited[v] == False:
				temp = []
				cc.append(self.DFSUtil(temp, v, visited))
		return cc

class MergeFind:

	def __init__(self, n):
		self.parent = list(range(n))
		self.size = [1] * n
		self.num_sets = n
		self.lista = [[_] for _ in range(n)]

	def find(self, a):
		to_update = []
		while a != self.parent[a]:
			to_update.append(a)
			a = self.parent[a]
		for b in to_update:
			self.parent[b] = a
		return self.parent[a]

	def merge(self, a, b):
		a = self.find(a)
		b = self.find(b)
		if a == b:
			return
		if self.size[a] < self.size[b]:
			(a, b) = (b, a)
		self.num_sets -= 1
		self.parent[b] = a
		self.size[a] += self.size[b]
		self.lista[a] += self.lista[b]
		self.lista[b] = []

	def set_size(self, a):
		return self.size[self.find(a)]

	def __len__(self):
		return self.num_sets
if os.path.exists('in.txt'):
	sys.stdin = open('in.txt', 'r')
if os.path.exists('out.txt'):
	sys.stdout = open('out.txt', 'w')

def inp():
	return sys.stdin.readline()

def out(var):
	sys.stdout.write(str(var) + '\n')

def I():
	return inp()

def II():
	return int(inp())

def FI():
	return float(inp())

def SI():
	return list(str(inp()))

def MI():
	return map(int, inp().split())

def LI():
	return list(MI())

def SLI():
	return sorted(LI())

def MF():
	return map(float, inp().split())

def LF():
	return list(MF())

def SLF():
	return sorted(LF())
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
MOD = 998244353
mod = 10 ** 9 + 7

def __starting_point():
	for ii in range(II()):
		n = II()
		print(''.join(I().split()))
__starting_point()


for _ in range(int(input())):
	n = int(input())
	arr = input().split()
	print(''.join(arr))


for e in range(int(input())):
	n = int(input())
	l = list(map(str, input().split()))
	print(''.join(l))


for _ in range(int(input())):
	n = int(input())
	l = list(map(str, input().split()))
	a = []
	for i in l:
		a.append(i)
	print(''.join(a))


for _ in range(int(input())):
	n = int(input())
	l = [x for x in input().split()]
	print(''.join(l))


t = int(input())
for _ in range(t):
	n = int(input())
	a = [x for x in input().split()]
	print(''.join(a))


t = int(input())
for i in range(t):
	n = int(input())
	l = list(map(int, input().split()))
	for i in range(n - 1):
		print(l[i], end='')
	print(l[n - 1])


for _ in range(int(input())):
	n = int(input())
	print(*list(map(int, input().split())), sep='')


for _ in range(int(input())):
	N = int(input())
	print(''.join(input().split(' ')))


from sys import stdin, stdout
from math import gcd
st = lambda : list(stdin.readline().strip())
li = lambda : list(map(int, stdin.readline().split()))
mp = lambda : map(int, stdin.readline().split())
inp = lambda : int(stdin.readline())
pr = lambda n: stdout.write(str(n) + '\n')
mod = 1000000007

def solve():
	n = inp()
	l = li()
	pr(''.join(list(map(str, l))))
for _ in range(inp()):
	solve()


for _ in range(int(input())):
	n = int(input())
	print(input().replace(' ', ''))


from sys import stdin
for _ in range(int(stdin.readline())):
	n = int(stdin.readline())
	ls = list(map(int, stdin.readline().split()))
	print(*ls, sep='')


for T in range(int(input())):
	N = int(input())
	print(*map(int, input().split()), sep='')