Description
Assume you have a square of size n that is divided into n × n positions just as a checkerboard. Two positions (x1, y1) and (x2, y2), where 1 ≤ x1, y1, x2, y2 ≤ n, are called “independent” if they occupy different rows and different columns, that is, x1 ≠ x2 and y1 ≠ y2. More generally, n positions are called independent if they are pairwise independent. It follows that there are n! different ways to choose n independent positions.
Assume further that a number is written in each position of such an n × n square. This square is called “homogeneous” if the sum of the numbers written in n independent positions is the same, no matter how the positions are chosen. Write a program to determine if a given square is homogeneous!
Input
The input contains several test cases.
The first line of each test case contains an integer n (1 ≤ n ≤ 1000). Each of the next n lines contains n numbers, separated by exactly one space character. Each number is an integer from the interval [−1000000, 1000000].
The last test case is followed by a zero.
Output
For each test case output whether the specified square is homogeneous or not. Adhere to the format shown in the sample output.
Sample Input
2
1 2
3 4
3
1 3 4
8 6 -2
-3 4 0
0
Sample Output
homogeneous
not homogeneous
http://blog.csdn.net/a605281436/article/details/7641833
