Hide

Problem A
Texture Analysis

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

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.

Output

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 not.

Sample Input 1 Sample Output 1
*.*.*.*.*.*.*.*.*
*..*.*.*.*.*.*.*.*
*..*..*
*
***
*.**
END
1 EVEN
2 NOT EVEN
3 EVEN
4 EVEN
5 EVEN
6 NOT EVEN

Please log in to submit a solution to this problem

Log in