题目描述
We have a grid with $H$ rows from top to bottom and $W$ columns from left and right. Initially, the square at the $i$\-th row from the top and $j$\-th column from the left has a lowercase English letter $A_{i,j}$.
Let us perform $Q$ operations on this grid. In the $i$\-th operation, we are given integers $a_i$ and $b_i$ such that $1\leq a_i \leq H-1$ and $1\leq b_i\leq W-1$, and do the following.
- Let $R_1$, $R_2$, $R_3$, and $R_4$ be rectangular regions within the grid defined as follows:
- $R_1$ is the intersection of the top $a_i$ rows and leftmost $b_i$ columns;
- $R_2$ is the intersection of the top $a_i$ rows and rightmost $W-b_i$ columns;
- $R_3$ is the intersection of the bottom $H-a_i$ rows and leftmost $b_i$ columns;
- $R_4$ is the intersection of the bottom $H-a_i$ rows and rightmost $W-b_i$ columns.
- Rotate $180$ degrees each of $R_1$, $R_2$, $R_3$, and $R_4$.
Here, a $180$\-degree rotation of a rectangular region $R$ within the grid moves the character on the square at the $i$\-th from the top and $j$\-th column from the left in $R$ to the square at the $i$\-th from the bottom and $j$\-th column from the right in $R$. See also the figures for the samples.
Print the grid after all $Q$ operations.
输入格式
The input is given from Standard Input in the following format:
> $H$ $W$
$A_{1,1}\cdots A_{1, W}$
$\vdots$
$A_{H,1}\cdots A_{H, W}$
$Q$
$a_1$ $b_1$
$\vdots$
$a_Q$ $b_Q$
#### Constraints
- $2\leq H, W$, and $HW \leq 5\times 10^5$.
- $A_{i,j}$ is a lowercase English letter.
- $1\leq Q\leq 2\times 10^5$
- $1\leq a_i\leq H - 1$
- $1\leq b_i\leq W - 1$
输出格式
Print the grid after the operations in the following format, where $B_{i,j}$ is the character on the square $(i,j)$ on the final grid.
> $B_{1,1}\cdots B_{1, W}$
$\vdots$
$B_{H,1}\cdots B_{H, W}$
样例输入 #1
4 5 abcde fghij klmno pqrst 1 3 3
样例输出 #1
mlkon hgfji cbaed rqpts
样例输入 #2
3 7 atcoder regular contest 2 1 1 2 5
样例输出 #2
testcon oderatc ularreg
样例输入 #3
2 2 ac wa 3 1 1 1 1 1 1
样例输出 #3
ac wa