A boy lost the password of his super locker. He remembers the number of digits N as well as the sum S of all the digits of his password. He know that his password is the largest number of N digits that can be possible with given sum S. As he is busy doing his homework, help him retrieving his password.

Input: The first line of input contains an integer T denoting the number of test cases. Then T test cases follow. The first line of each test case contains two space separated integers N and S, where N is the number of digits in password and S is the sum of all the digits of the password.

Output:
Corresponding to each test case, in a new line, print the largest integer if possible , else print -1.

Constraints:
1 <= T <= 100
1 <= N <= 10^{4}
0 <= S <= 10^{6}

Example: Input: 3
5 12
3 29
3 26

Output:
93000
-1
998

Explanation : Testcase 1: Sum of elements is 12. Largest possible 5 digit number is 93000. Testcase 2: There is no such three digit number whose sum is 29.