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.

Difficulty: interview

Starter code:

Solutions:
"""
    Author : thekushalghosh
    Team   : CodeDiggers
"""
import sys,math
input = sys.stdin.readline
############ ---- USER DEFINED INPUT FUNCTIONS ---- ############
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()))
################################################################
############ ---- THE ACTUAL CODE STARTS BELOW ---- ############
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)