密码

★实验任务

小米终于来到了学校，很高兴，他解决了学长留给他的问题，得到了学长的赞赏。他打

点行李回寝室去了，到了宿舍门口才发现这里的门居然不是用钥匙开的，怪不得刚才小米

就觉得奇怪，怎么没有发钥匙，经过小米的仔细“研究”，终于发现这是个密码锁。

这个密码锁很奇怪，密码提示是一串 1 到 n 的排列，他发现这个序列有一个规律：如果

i 出现，那么其后出现的小于 i 的数均为降序。原来是这么回事，小米恍然大悟。门上只有

两个按键和一个竖槽，一个是 PUSH 键，另一个 POP 键。系统每次从槽顶掉入一个数字卡

片（从 1 到 n），PUSH 代表把该数放入暂存槽（后入先出），POP 代表从暂存槽取出一个数

作为当前你要输入的密码。如下图所示：

众所周知，小米很懒，每次进门都要算，多麻烦啊，于是他就找你帮忙，给你一串序

列，其值为 1 到 n 的一个排列，输出形成该序列的操作。

★数据输入

输入首先为n（1<=n<=20000），接下去为1到n的一个排列。

★数据输出

输出形成该序列的操作，数据保证该序列可以形成。-Password

★ experimental tasks

Millet finally came to the school, I am glad that he left him to solve the problem of seniors, has been appreciated by seniors. He played

Point luggage went back to the bedroom, only to find the entrance to the dormitory where the door is not actually opened with a key, just wonder millet

To wonder, how did not send the key, after millet careful "research", and finally found this to be a lock.

This lock is very strange, the password prompt is a string of 1 to n, arranged, he found that this sequence has a rule: If

i there, then the subsequent number smaller than i are in descending order. That this was what, millet understood why. Only the door

Two buttons and a vertical slot, one PUSH key, another POP key. Fall from the top of each tank system, a digital card

Pieces (from 1 to n), PUSH representative to the number in temporary tanks (after first-out), POP out on behalf of a number from the temporary tank

As you enter the current password. As show