Letter "Y" on a Square Matrix

You are given a square matrix of odd order whose cell values are only 0, 1, or 2. Choose one digit as the digit of the Y: its upper part consists of the two diagonals running from the top-left corner to the center and from the top-right corner to the center, and below the center it is the middle column; every cell outside the Y must become one other, different digit. Find the minimum number of cells that must be changed.

Standard input/output, this site's supplementary ranges, and the examples follow this problem's description.

输入格式

The first line contains an odd n (1≤n≤99), followed by n lines, each with n values of 0, 1, or 2. The upper bound on n is a site supplement.

输出格式

Output the minimum number of cells to change.

样例 1

输入：

3
1 0 1
2 1 2
2 1 2

输出：

1

样例 2

输入：

5
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 0 0

输出：

7

样例 3

输入：

3
0 1 2
1 2 0
2 0 1

输出：

4