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A8963 | $Multithreading$

时间限制1s

内存限制256MB

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题目描述

The first line of input contains an integer $n$ , the number of threads ( $1<=n<=10^{5}$ ). The next line contains a list of $n$ space-separated integers $a_{1}$ , $a_{2}$ , ..., $a_{n}$ where $a_{i}$ ( $1<=a_{i}<=n$ ) is the old position of the $i$ -th thread in the new list. It is guaranteed that all of the $a_{i}$ are distinct.

输入格式

Output a single integer — the number of threads that surely contain a new message.

输出格式

In the first test case, threads 2 and 5 are placed before the thread 1, so these threads must contain new messages. Threads 1, 3 and 4 may contain no new messages, if only threads 2 and 5 have new messages. In the second test case, there may be no new messages at all, since the thread order hasn't changed. In the third test case, only thread 1 can contain no new messages.

输入输出样例

输入 #1

5
5 2 1 3 4

输出 #1

输入 #2

3
1 2 3

输出 #2

输入 #3

4
4 3 2 1

输出 #3

C++ 编辑器

输入

输出