Codeforces Round 256 (Div. 2)
B
Suffix Structures
Codeforces
1400
原题
← AC →
翻译中…

Bizon the Champion isn't just a bison. He also is a favorite of the "Bizons" team.

翻译中…

At a competition the "Bizons" got the following problem: "You are given two distinct words (strings of English letters), $*s*$ and $*t*$. You need to transform word $*s*$ into word $*t*$". The task looked simple to the guys because they know the suffix data structures well. Bizon Senior loves suffix automaton. By applying it once to a string, he can remove from this string any single character. Bizon Middle knows suffix array well. By applying it once to a string, he can swap any two characters of this string. The guys do not know anything about the suffix tree, but it can help them do much more.

翻译中…

Bizon the Champion wonders whether the "Bizons" can solve the problem. Perhaps, the solution do not require both data structures. Find out whether the guys can solve the problem and if they can, how do they do it? Can they solve it either only with use of suffix automaton or only with use of suffix array or they need both structures? Note that any structure may be used an unlimited number of times, the structures may be used in any order.

翻译中…

Input

翻译中…

The first line contains a non-empty word $*s*$. The second line contains a non-empty word $*t*$. Words $*s*$ and $*t*$ are different. Each word consists only of lowercase English letters. Each word contains at most 100 letters.

翻译中…

Output

翻译中…

In the single line print the answer to the problem. Print "need tree" (without the quotes) if word $*s*$ cannot be transformed into word $*t*$ even with use of both suffix array and suffix automaton. Print "automaton" (without the quotes) if you need only the suffix automaton to solve the problem. Print "array" (without the quotes) if you need only the suffix array to solve the problem. Print "both" (without the quotes), if you need both data structures to solve the problem.

翻译中…

It's guaranteed that if you can solve the problem only with use of suffix array, then it is impossible to solve it only with use of suffix automaton. This is also true for suffix automaton.

翻译中…

Note

翻译中…

In the third sample you can act like that: first transform "both" into "oth" by removing the first character using the suffix automaton and then make two swaps of the string using the suffix array and get "hot".

翻译中…

样例

Input #1
automaton
tomat
Output #1
automaton
InputCopy OutputCopy
Input #2
array
arary
Output #2
array
InputCopy OutputCopy
Input #3
both
hot
Output #3
both
InputCopy OutputCopy
Input #4
need
tree
Output #4
need tree
InputCopy OutputCopy
题目信息
题号
448B
时间限制
1 s
内存限制
256 MB
标签
模拟
字符串

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