Pine

Christmas is approaching, so Péter is setting up a Christmas tree. To build the tree, he uses odd-length elements made entirely of x’s - x, xxx, xxxxx, ... - and odd-length elements that have x’s on the edges and dots (.) inside - x, x.x, x..x, x...x, .... The structure of the tree is shown in the diagram below:

   x         Top part
  x.x
 x...x       Leaf section
x.....x
  x.x
 x...x       Leaf section
x.....x
  x.x
 x...x       Leaf section
x.....x
  xxx
  xxx        Trunk
  xxx
  xxx

The top part of the tree is always a single x. For this tree, there are $N=3$ leaf sections, each with a height of $M=3$, and the shortest element in the leaf sections is always x.x. The trunk is $H=4$ high and $W=3$ wide. Unfortunately, the tree exists only as a thought in Péter’s mind — it’s up to you to write the program that will create it.”

Input specification

A single line with the positive integers $N\ M\ H\ W$, separated by a space.

Output specification

A tree that matches the parameters. All alignments should be done with spaces, but there should be no unnecessary characters at the end of the lines.

Constraints

$2\le N \le 42$
$3\le M \le 42$
$2\le H \le 42$
$1\le W \le 42$
$W$ is always an odd integer and less than $2M+1$.

Sample input 1

1. 3 3 4 3

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Sample output 1

1.    x
2.   x.x
3.  x...x
4. x.....x
5.   x.x
6.  x...x
7. x.....x
8.   x.x
9.  x...x
10. x.....x
11.   xxx
12.   xxx
13.   xxx
14.   xxx

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Sample input 2

1. 3 4 6 1

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Sample output 2

1.     x
2.    x.x
3.   x...x
4.  x.....x
5. x.......x
6.    x.x
7.   x...x
8.  x.....x
9. x.......x
10.    x.x
11.   x...x
12.  x.....x
13. x.......x
14.     x
15.     x
16.     x
17.     x
18.     x
19.     x

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