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A9295. Fox and Cross

编程题 普及/提高-

题目描述

Fox Ciel has a board with $n$ rows and $n$ columns. So, the board consists of $n×n$ cells. Each cell contains either a symbol '.', or a symbol '\#'.

A cross on the board is a connected set of exactly five cells of the board that looks like a cross. The picture below shows how it looks.

![](/uploads/acgo/image/bbed2e9a703539b6_5bac27bbce09.jpeg)Ciel wants to draw several (may be zero) crosses on the board. Each cross must cover exactly five cells with symbols '\#', and any cell with symbol '\#' must belong to some cross. No two crosses can share a cell.

Please, tell Ciel if she can draw the crosses in the described way.

输入格式

The first line contains an integer $n$ ( $3<=n<=100$ ) — the size of the board.

Each of the next $n$ lines describes one row of the board. The $i$ -th line describes the $i$ -th row of the board and consists of $n$ characters. Each character is either a symbol '.', or a symbol '\#'.

输出格式

Output a single line with "YES" if Ciel can draw the crosses in the described way. Otherwise output a single line with "NO".

输入输出样例

输入 #1
5
.#...
####.
.####
...#.
.....
输出 #1
YES
输入 #2
4
####
####
####
####
输出 #2
NO
输入 #3
6
.#....
####..
.####.
.#.##.
######
.#..#.
输出 #3
YES
输入 #4
6
.#..#.
######
.####.
.####.
######
.#..#.
输出 #4
NO
输入 #5
3
...
...
...
输出 #5
YES

说明/提示

In example 1, you can draw two crosses. The picture below shows what they look like.

![](/uploads/acgo/image/4ae589fd6d3f8da3_e9a783ac68f6.jpeg)In example 2, the board contains 16 cells with '\#', but each cross contains 5. Since 16 is not a multiple of 5, so it's impossible to cover all.
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