Ashley wrote a random number generator code.
Due to some reasons, the code only generates random positive integers which are not evenly divisible by 10. She gives $N$ and $S$ as input to the random number generator. The code generates a random number with number of digits equal to $N$ and sum of digits equal to $S$. The code returns -1 if no number can be generated. Print "-1" in such cases (without quotes). Else print the minimum possible product of digits of the random number generated.

-----Input:-----
- First line will contain a single integer $T$, the number of testcases. 
- Each testcase consists of two space separated integers, $N$ and $S$. 

-----Output:-----
For each testcase, output the answer on a new line.

-----Constraints-----
- $1 \leq T \leq 10^5$
- $1 \leq N \leq 18$
- $1 \leq S \leq 5 * N$

-----Sample Input:-----
2
1 5

2 2

-----Sample Output:-----
5

1

-----EXPLANATION:-----
In first testcase, the only possible number of length 1 having digit sum 5 is 5. And it's product of digits is 5. 
In second testcase,  only possible two digit number as a generator output is 11(as 20 is divisible by 10, it is never generated) and product of it's digits is 1.

Source: codechef | Difficulty: UNKNOWN_DIFFICULTY


Solutions:
import sys, math
input = sys.stdin.readline

def inp():
	return int(input())

def inlt():
	return list(map(int, input().split()))

def insr():
	s = input()
	return s[:len(s) - 1]

def invr():
	return map(int, input().split())
t = 1
t = inp()
for tt in range(t):
	(n, s) = invr()
	if n == 2 and s > 1:
		print(s - 1)
	elif n > 2 and s > 1:
		print(0)
	elif n == 1:
		print(s)
	else:
		print(-1)


for t in range(int(input())):
	(n, s) = [int(i) for i in input().split()]
	if n == 1:
		print(s)
		continue
	if s < 2:
		print(-1)
		continue
	if n == 2:
		print(s - 1)
		continue
	l = [0 for i in range(n)]
	s -= 18
	l[0] = 9
	l[-1] = 9
	if s <= 0:
		print(0)
		continue
	res = 1
	for i in range(n):
		temp = min(s, 9 - l[i])
		l[i] += temp
		s -= temp
		res = res * l[i]
		i += 1
	print(res)