You are writing an analysis program that identifies textures
in black-and-white images. One subroutine in this program is
supposed to detect whether an entire row of pixels is covered
by a pattern of regularly-spaced black pixels. That is, it
determines if every pair of adjacent black pixels is separated
by the same number of white pixels.
Write a program that simulates this subroutine using a
textual input representation. Each row of image pixels is
represented by a single line of text. Each asterisk (*) represents a black pixel, while each period
(.) represents a white pixel.
The following line is an example of evenly-spaced black
pixels, since each pair of adjacent black pixels are separated
by two white pixels.
The following line is NOT an example of evenly-spaced black
pixels, since the two leftmost black pixels are separated by
four white pixels, but each remaining pair of adjacent black
pixels are separated by three white pixels.
Input to your program consists of a sequence of lines, at
most $2\, 000$. Each line
is one row of pixels to be analyzed. Every line will start and
end with a black pixel, and every line will contain only black
pixels and white pixels. No line will have more than
$1\, 000$ characters.
The last line to process is followed by a line containing
the word END.
For each line, print the line number followed by EVEN if the black pixels on that line are
evenly-spaced, or NOT EVEN if they are
|Sample Input 1
||Sample Output 1
2 NOT EVEN
6 NOT EVEN