#P677E. Vanya and Balloons

    ID: 5237 远端评测题 3000ms 512MiB 尝试: 0 已通过: 0 难度: 8 上传者: 标签>binary searchbrute forcedpimplementation*2300

Vanya and Balloons

Description

Vanya plays a game of balloons on the field of size n × n, where each cell contains a balloon with one of the values 0, 1, 2 or 3. The goal is to destroy a cross, such that the product of all values of balloons in the cross is maximum possible. There are two types of crosses: normal and rotated. For example:


**o**
**o**
ooooo
**o**
**o**

or


o***o
*o*o*
**o**
*o*o*
o***o

Formally, the cross is given by three integers r, c and d, such that d ≤ r, c ≤ n - d + 1. The normal cross consists of balloons located in cells (x, y) (where x stay for the number of the row and y for the number of the column), such that |x - r|·|y - c| = 0 and |x - r| + |y - c| < d. Rotated cross consists of balloons located in cells (x, y), such that |x - r| = |y - c| and |x - r| < d.

Vanya wants to know the maximum possible product of the values of balls forming one cross. As this value can be large, output it modulo 109 + 7.

The first line of the input contains a single integer n (1 ≤ n ≤ 1000) — the number of rows and columns in the table with balloons.

The each of the following n lines contains n characters '0', '1', '2' or '3' — the description of the values in balloons.

Print the maximum possible product modulo 109 + 7. Note, that you are not asked to maximize the remainder modulo 109 + 7, but to find the maximum value and print it this modulo.

Input

The first line of the input contains a single integer n (1 ≤ n ≤ 1000) — the number of rows and columns in the table with balloons.

The each of the following n lines contains n characters '0', '1', '2' or '3' — the description of the values in balloons.

Output

Print the maximum possible product modulo 109 + 7. Note, that you are not asked to maximize the remainder modulo 109 + 7, but to find the maximum value and print it this modulo.

4<br>1233<br>0213<br>2020<br>0303<br>
5<br>00300<br>00300<br>33333<br>00300<br>00300<br>
5<br>00003<br>02030<br>00300<br>03020<br>30000<br>
5<br>21312<br>10003<br>10002<br>10003<br>23231<br>
5<br>12131<br>12111<br>12112<br>21311<br>21212<br>
108<br>
19683<br>
108<br>
3<br>
24<br>

Note

In the first sample, the maximum product is achieved for a rotated cross with a center in the cell (3, 3) and radius 1: 2·2·3·3·3 = 108.