CF1005A.Tanya and Stairways

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.

小女孩塔尼娅在一座多层建筑内爬楼梯。每次塔尼娅爬一段楼梯时，她都会从 $1$ 开始，一直数到该段楼梯的总阶数为止。她会大声读出每一个数字。例如，如果她爬了两段楼梯，第一段有 $3$ 阶，第二段有 $4$ 阶，那么她将依次读出数字 $1, 2, 3, 1, 2, 3, 4$。

现给出塔尼娅所读出的所有数字序列。请问她一共爬了多少段楼梯？并输出每段楼梯的阶数。

给定的序列是合法的，即它确实可能是塔尼娅在爬一段或多段楼梯时所读出的序列。

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.

第一行包含一个整数 $n$（$1 \le n \le 1000$）—— 表示塔尼娅报出的数字总数。

第二行包含 $n$ 个整数 $a_1, a_2, \dots, a_n$（$1 \le a_i \le 1000$）—— 表示塔尼娅在爬楼梯过程中按顺序报出的所有数字，从第一个报出的数字到最后一个报出的数字。当她经过一段有 $x$ 级台阶的楼梯时，她将按顺序报出数字 $1, 2, \dots, x$。

给定的序列是塔尼娅在爬一段或多段楼梯时可能报出的有效序列。

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.

第一行输出 $t$ —— 塔尼娅爬过的楼梯段数。
第二行输出 $t$ 个数字 —— 她爬过的每段楼梯的阶数。请按塔尼娅经过楼梯段的正确顺序写出这些数字。