Problem:
Score : 500 points

Problem Statement

Snuke has two boards, each divided into a grid with N rows and N columns.
For both of these boards, the square at the i-th row from the top and the j-th column from the left is called Square (i,j).

There is a lowercase English letter written in each square on the first board. The letter written in Square (i,j) is S_{i,j}. On the second board, nothing is written yet.

Snuke will write letters on the second board, as follows:

First, choose two integers A and B ( 0 \leq A, B < N ).

Write one letter in each square on the second board.
Specifically, write the letter written in Square ( i+A, j+B ) on the first board into Square (i,j) on the second board.
Here, the k-th row is also represented as the (N+k)-th row, and the k-th column is also represented as the (N+k)-th column.

After this operation, the second board is called a good board when, for every i and j ( 1 \leq i, j \leq N ), the letter in Square (i,j) and the letter in Square (j,i) are equal.

Find the number of the ways to choose integers A and B ( 0 \leq A, B < N ) such that the second board is a good board.

Constraints

1 \leq N \leq 300

S_{i,j} ( 1 \leq i, j \leq N ) is a lowercase English letter.

Input

Input is given from Standard Input in the following format:

N
S_{1,1}S_{1,2}..S_{1,N}
S_{2,1}S_{2,2}..S_{2,N}
:
S_{N,1}S_{N,2}..S_{N,N}

Output

Print the number of the ways to choose integers A and B ( 0 \leq A, B < N ) such that the second board is a good board.

Sample Input 1

2
ab
ca

Sample Output 1

2

For each pair of A and B, the second board will look as shown below:

The second board is a good board when (A,B) = (0,1) or (A,B) = (1,0), thus the answer is 2.

Sample Input 2

4
aaaa
aaaa
aaaa
aaaa

Sample Output 2

16

Every possible choice of A and B makes the second board good.

Sample Input 3

5
abcde
fghij
klmno
pqrst
uvwxy

Sample Output 3

0

No possible choice of A and B makes the second board good.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int N = sc.nextInt();
int answer=0;
char[][] input = new char[N][N];
char[][] output = new char[N][N];
boolean[][] count = new boolean[N][N];
for(int j=0;j<N;j++){
  String s=sc.next();
  for(int i=0;i<N;i++){
    count[i][j]=true;
char[] carr = s.toCharArray();
    input[i][j]=carr[j];
  }
}
for(int A=0;A<N;A++){
  for(int B=0;B<N;B++){
    for(int j=0;j<N;j++){
      for(int i=0;i<N;i++){
        output[(i+A)%N][(j+B)%N]=input[i][j];
      }
    }
    outer:for(int j=0;j<N;j++){
      for(int i=0;i<j;i++){
        if(output[i][j]!=output[j][i])
        count[A][B]=false;
        break outer;
      }
    }
  }
}
for(int j=0;j<N;j++){
  for(int i=0;i<N;i++){
    if(count[i][j])
    answer++;
  }
}
System.out.println(answer);
}
}