Ice rink#1940
Businessman Nikolai is passionate about ice skating. Every year on December 31st, he gathers his friends, rents an ice rink, and celebrates the New Year with joy. Recently, Nikolai thought it would be wonderful to have his own ice rink, allowing him to skate whenever he pleases without any cost. Without hesitation, he decided to pursue this idea and hired architect Dmitry to make it happen.
Dmitry discovered that Nikolai's favorite number is , and he loves skating along the edge. To delight his client, Dmitry planned to design an ice rink where skating along the entire perimeter would cover exactly hundred meters. He was close to finalizing the design when Nikolai added another requirement: the rink must have an area of exactly tens of thousands of square meters (a smaller area wouldn't accommodate all of Nikolai's friends, and a larger one would be too costly).
If any part of the rink borders an area not part of the rink, a barrier must be constructed there. Barriers cannot be placed arbitrarily within the rink; they are only allowed on its boundary.
The rink will be constructed near Nikolai's cottage, on a square plot with sides measuring meters. The design must ensure that all corners of the rink are right angles, the lengths of the barriers are multiples of meters, and the barriers run parallel to the sides of the plot.
Help Dmitry come up with a rink plan that satisfies all the requirements.
The input consists of a single line containing two integers and (1 \leq P \leq 40, 1 \leq S \leq 16) — representing the perimeter and area of the future rink, respectively.
Output Impossible if it is not feasible to design a rink that meets the specified requirements.
Otherwise, output lines with characters each, representing the plan of the new rink. Each character corresponds to a 100 \times 100 meter square of the plot. If the square is part of the rink, output "*"; otherwise, output ".".
Example 1