Given two numbers 'N' and 'S' , find the largest number that can be formed with 'N' digits and whose sum of digits should be equals to 'S'.
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 and S is the sum.
Print the largest number that is possible.
If their is no such number, then print -1
1 <= T <= 30
1 <= N <= 50
0 <= S <= 500
Expected Time Complexity: O(n)