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时间限制: 2 s 内存限制: 256 MB 总分: 100 可 Hack ✓

#21705. 【NOIP Round #4】Sequence

统计

Today is YQH's birthday, and she received an integer sequence $a_1, a_2, \dots, a_n$ of length $n$ as a birthday gift.

However, YQH is not satisfied with this sequence because it might not be valid.

A sequence $\{a_i\}$ is valid if and only if $\max\limits_{i=1}^n\{a_i\} + \min\limits_{i=1}^n\{a_i\} > n$, where $n$ is the length of the sequence. Specifically, we define $\varnothing$ as valid.

To make YQH satisfied, you need to find a subsegment of $a_1, a_2, \dots, a_n$ that is valid. A sequence $b_1, b_2, \dots, b_m$ is a subsegment of $a_1, a_2, \dots, a_n$ if and only if $b_1, b_2, \dots, b_m$ can be obtained by removing some (possibly zero) elements from the beginning and the end of $a_1, a_2, \dots, a_n$. For example, $[2,3], [1,2], [3,4], [1,2,3,4], \varnothing$ are all subsegments of $[1,2,3,4]$.

There may be many valid subsegments, so YQH only wants you to find the maximum length among all valid subsegments of $a_1, a_2, \dots, a_n$.

However, the sequence YQH received is magical and changes over time. YQH wants you to find the answer for the initial sequence and after each change.

Input

The first line contains a positive integer $n$ and a non-negative integer $m$, where $m$ is the number of changes to $\{a_i\}$.

The second line contains $n$ integers representing the initial $a_1, a_2, \dots, a_n$.

Next, $m$ changes are described, each consisting of several lines:

The first line contains a non-negative integer $k$. The next $k$ lines each contain two positive integers $x_i, y_i$. If the sequence before the change is $\{a_i\}$, then after sequentially swapping $(a_{x_1}, a_{y_1}), (a_{x_2}, a_{y_2}), \dots, (a_{x_k}, a_{y_k})$, the resulting sequence $\{a^\prime_i\}$ is the sequence after the change.

Changes are not independent (see sample explanation).

Output

The first line contains an integer representing the answer for the initial $\{a_i\}$.

The next $m$ lines each contain an integer representing the answer after the $i$-th change.

Examples

Input 1

5 2
1 2 -2 3 4
1
2 3
1
1 2

Output 1

2
3
4

Note 1

The initial $\{a_i\}$ is $[1,2,-2,3,4]$, and one valid subsegment is $[3,4]$.

After the first change, swapping $(a_2, a_3)$ results in $\{a_i\}$ being $[1,-2,2,3,4]$, and one valid subsegment is $[2,3,4]$.

After the second change, swapping $(a_1, a_2)$ results in $\{a_i\}$ being $[-2,1,2,3,4]$, and one valid subsegment is $[1,2,3,4]$.

Input 2

5 2
-1 -1 2 1 1
2
3 4
2 5
2
2 5
1 4

Output 2

2
2
1

Note 2

The initial $\{a_i\}$ is $[-1,-1,2,1,1]$, and one valid subsegment is $[2,1]$.

After the first change, first swap $(a_3, a_4)$, then swap $(a_2, a_5)$, resulting in $\{a_i\}$ being $[1,1,1,2,-1]$, and one valid subsegment is $[1,2]$.

After the second change, first swap $(a_2, a_5)$, then swap $(a_1, a_4)$, resulting in $\{a_i\}$ being $[2,-1,1,1,1]$, and one valid subsegment is $[1]$.

Examples 3

See ex_loose3.in/ex_loose3.ans in the provided files.

Examples 4

See ex_loose4.in/ex_loose4.ans in the provided files.

Constraints

Let $K$ be the sum of the number of swaps $k$ across all changes.

For all data, it is guaranteed that $1 \le n \le 10^6, 0 \le m \le 30, 0 \le K \le 10^6, |a_i| \le 10^9, x_i \ne y_i$.

Subtask $n \le$ $m \le$ Score
$1$ $2000$ $30$ $20$
$2$ $2\times10^5$ $2$ $20$
$3$ $10^6$ $2$ $20$
$4$ $10^6$ $30$ $40$

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