CF719A.Vitya in the Countryside

Every summer Vitya comes to visit his grandmother in the countryside. This summer, he got a huge wart. Every grandma knows that one should treat warts when the moon goes down. Thus, Vitya has to catch the moment when the moon is down.

Moon cycle lasts 30 days. The size of the visible part of the moon (in Vitya's units) for each day is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and then cycle repeats, thus after the second 1 again goes 0.

As there is no internet in the countryside, Vitya has been watching the moon for n consecutive days and for each of these days he wrote down the size of the visible part of the moon. Help him find out whether the moon will be up or down next day, or this cannot be determined by the data he has.

每年夏天，维佳都会去乡下看望他的祖母。今年夏天，他长了一个很大的疣。每位祖母都知道，应该在月亮“下落”时治疗疣。因此，维佳必须抓住月亮正在下落的那一刻。

月相周期为 30 天。月亮可见部分的大小（以维佳的单位计）每天依次为：
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1，然后循环重复；即第二个 1 之后再次变为 0。

由于乡下没有互联网，维佳已连续观察了 n 天的月亮，并将这 n 天中每天月亮可见部分的大小记录了下来。请帮助他判断：明天月亮是“上升”还是“下降”，或者根据他所掌握的数据无法确定。

The first line of the input contains a single integer n (1 ≤ n ≤ 92) — the number of consecutive days Vitya was watching the size of the visible part of the moon.

The second line contains n integers a__i (0 ≤ a__i ≤ 15) — Vitya's records.

It's guaranteed that the input data is consistent.

输入的第一行包含一个整数 $n$（$1 ≤ n ≤ 92$）—— 表示维佳连续观察月球可见部分大小的天数。

第二行包含 $n$ 个整数 $a_i$（$0 ≤ a_i ≤ 15$）—— 维佳的观测记录。

保证输入数据是自洽的。

If Vitya can be sure that the size of visible part of the moon on day n + 1 will be less than the size of the visible part on day n, then print "DOWN" at the only line of the output. If he might be sure that the size of the visible part will increase, then print "UP". If it's impossible to determine what exactly will happen with the moon, print -1.

如果维佳能够确定第 $n+1$ 天月亮可见部分的大小将小于第 $n$ 天的大小，则在输出的唯一一行中打印 “DOWN”。
如果他能够确定月亮可见部分的大小将会增大，则打印 “UP”。
如果无法确定月亮可见部分大小的具体变化情况，则打印 -1。

In the first sample, the size of the moon on the next day will be equal to 8, thus the answer is "UP".

In the second sample, the size of the moon on the next day will be 11, thus the answer is "DOWN".

In the third sample, there is no way to determine whether the size of the moon on the next day will be 7 or 9, thus the answer is -1.

在第一个样例中，第二天的月相大小为 8，因此答案为 “UP”。

在第二个样例中，第二天的月相大小为 11，因此答案为 “DOWN”。

在第三个样例中，无法确定第二天的月相大小是 7 还是 9，因此答案为 $-1$。