# CF1005A Tanya and Stairways

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• 237提交
• 题目来源
• 评测方式 RemoteJudge
• 标签 概率论,统计 模拟
• 难度 入门难度
• 时空限制 1000ms / 256MB
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## 题意翻译

题目描述：

给你N个数（1≤N≤1000），这N个数是由M个从1开始的连续自然序列组成的

输入输出格式：

输入格式：

第一行，一个数：N

第二行N个数，分别是组成M个序列的元素

输出格式：

第一行，一个数：M

第二行，M个数，分别是这M个序列的长度

## 题目描述

Little girl Tanya climbs the stairs inside a multi-storey building. Every time Tanya climbs a stairway, she starts counting steps from $1$ to the number of steps in this stairway. She speaks every number aloud. For example, if she climbs two stairways, the first of which contains $3$ steps, and the second contains $4$ steps, she will pronounce the numbers $1, 2, 3, 1, 2, 3, 4$ .

You are given all the numbers pronounced by Tanya. How many stairways did she climb? Also, output the number of steps in each stairway.

The given sequence will be a valid sequence that Tanya could have pronounced when climbing one or more stairways.

## 输入输出格式

输入格式：

The first line contains $n$ ( $1 \le n \le 1000$ ) — the total number of numbers pronounced by Tanya.

The second line contains integers $a_1, a_2, \dots, a_n$ ( $1 \le a_i \le 1000$ ) — all the numbers Tanya pronounced while climbing the stairs, in order from the first to the last pronounced number. Passing a stairway with $x$ steps, she will pronounce the numbers $1, 2, \dots, x$ in that order.

The given sequence will be a valid sequence that Tanya could have pronounced when climbing one or more stairways.

输出格式：

In the first line, output $t$ — the number of stairways that Tanya climbed. In the second line, output $t$ numbers — the number of steps in each stairway she climbed. Write the numbers in the correct order of passage of the stairways.

## 输入输出样例

输入样例#1： 复制
7
1 2 3 1 2 3 4

输出样例#1： 复制
2
3 4 
输入样例#2： 复制
4
1 1 1 1

输出样例#2： 复制
4
1 1 1 1 
输入样例#3： 复制
5
1 2 3 4 5

输出样例#3： 复制
1
5 
输入样例#4： 复制
5
1 2 1 2 1

输出样例#4： 复制
3
2 2 1 
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