All Can Do

Construct a number N follows three below restrictions:
1. T-1 <= Log10N < T, ( 0 < T <= 100 )
2. 90 mod b = 0
3. N mod b = 0
Please help me find the biggest N.

The first line contains an integer t means the number of test cases.
Then each line will contain two integers T and b.

For each case, output N in one line, if there is no such answer, output "Impossible!".

3
2 45
1 10
2 5

90
Impossible!
95

HDU 2009-11 Programming Contest