Problem Statement

Given is a sequence p of length N+M, which is a permutation of $(1,2 \ldots, N+M)$.
The i-th term of p is p_i.
You can do the following Operation any number of times.
Operation: Choose an integer n between 1 and N (inclusive), and an integer m between 1 and M (inclusive). Then, swap p_{n} and p_{N+m}.
Find the minimum number of Operations needed to sort p in ascending order. We can prove that it is possible to sort p in ascending order under the Constraints of this problem.

Input

Input is given from Standard Input in the following format:
N M
$p_{1} \cdots p_{N+M}$

Output

Print the minimum number of Operations needed to sort p in ascending order.

Constraints

• All values in input are integers.
• $1 \leq N,M \leq 10^5$
• $1 \leq p_i \leq N+M$
• p is a permutation of $(1,2 \ldots, N+M)$.

Sample Input 1

2 3
1 4 2 5 3

Sample Output 1

3

Sample Input 2

5 7
9 7 12 6 1 11 2 10 3 8 4 5

Sample Output 2

10

见题面 Input 部分

见题面 Output 部分