330. Numbers
Time limit per test: 0.25 second(s)
Memory limit: 65536 kilobytes
input: standard
output: standard



Young Andrew is playing yet another numbers game. Initially, he writes down an integer A. Then, he chooses some divisor d1 of A, 1 < d1 < A, erases A and writes A1=A+d1 instead. Then, he chooses some divisor d2 of A1, 1 < d2 < A1, erases A1 and writes A2=A1+d2 instead.

I.e., at any step he chooses some positive integer divisor of the current number, but not 1 and not the whole number, and increases the current number by it.

Is it possible for him to write number B if he started with number A?

Input
The only line of input contains two integers A and B, 2 ≤ A < B ≤ 1012.

Output
If there's no solution, output "Impossible" (without quotes) to the only line of output. If there's one, output the sequence of numbers written starting with A and ending with B, one per line. You're not asked to find the shortest possible sequence, however, you should find a sequence with no more than 500 numbers. It is guaranteed that if there exists some sequence for the given A and B, then there exists a sequence with no more than 500 numbers in it.

Example(s)
sample input
sample output
12 57
12
16
24
27
30
40
50
52
54
57

sample input
sample output
3 6
Impossible
