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문제

Mr Singh은 NLCS Jeju의 선생님이다. Mr Singh은 현재 IB 과정 때문에 고통받는 12학년 학생들을 위해 수업 계획을 짜고 있다.

Mr Singh은 학생들이 받게 될 숙제의 순서인 숙제 계획을 짰다. 숙제 계획에는 $N$개의 숙제가 있으며, 각 숙제에는 $1$ 이상 $N$ 이하의 고유 번호가 부여된다.

선생님의 숙제 계획을 보고 분노한 학생들은 선생님에게 숙제 계획 요구안을 제시하였다.

Mr Singh은 학생들의 요구에 응하기로 하면서도, 커리큘럼을 망치고 싶지 않기 때문에, 다음 작업을 몇 번이든 실행하여 원래 숙제 계획을 요구안으로 바꿀 수 있는지 보고자 한다.

  • $3$개의 인접한 숙제를 선택하여 숙제 번호를 기준으로 오름차순 또는 내림차순으로 정렬한다.

Mr Singh이 위 작업을 몇 번이든 반복하여 원래 숙제 계획을 요구안으로 바꿀 수 있는지 조사하는 프로그램을 작성하시오.

입력

입력의 첫 번째 줄에 $N$이 주어진다.

입력의 두 번째 줄에 선생님의 원래 숙제 계획이 주어진다. $N$개의 서로 다른 정수가 공백으로 구분되어 주어지며, 모든 정수는 $1$ 이상 $N$ 이하이다.

입력의 세 번째 줄에 학생들이 제시한 요구안이 두 번째 줄과 같은 형식으로 주어진다.

출력

첫 번째 줄에 Mr Singh이 위 작업을 몇 번이든 실행하여 원래 숙제 계획을 요구안으로 바꿀 수 있는지를 출력한다. 가능하면 POSSIBLE을, 불가능하면 IMPOSSIBLE을 출력한다. 대소문자에 유의한다.

제한

  • $3 \leq N \leq 100\,000$

예제 입력 1

5
5 4 3 1 2
1 2 3 4 5

예제 출력 1

POSSIBLE

다음과 같은 과정을 거쳐 숙제 계획을 바꿀 수 있다.

  • 5 4 3 1 2
  • 3 4 5 1 2
  • 3 4 1 2 5
  • 3 1 2 4 5
  • 1 2 3 4 5

예제 입력 2

5
1 2 3 4 5
1 4 2 5 3

예제 출력 2

IMPOSSIBLE
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Mr Singh\uc740 \ud604\uc7ac IB \uacfc\uc815 \ub54c\ubb38\uc5d0 \uace0\ud1b5\ubc1b\ub294 12\ud559\ub144 \ud559\uc0dd\ub4e4\uc744 \uc704\ud574 \uc218\uc5c5 \uacc4\ud68d\uc744 \uc9dc\uace0 \uc788\ub2e4.<\/p>\r\n\r\n<p>Mr Singh\uc740 \ud559\uc0dd\ub4e4\uc774 \ubc1b\uac8c \ub420 \uc219\uc81c\uc758 \uc21c\uc11c\uc778 \uc219\uc81c \uacc4\ud68d\uc744 \uc9f0\ub2e4. \uc219\uc81c \uacc4\ud68d\uc5d0\ub294 $N$\uac1c\uc758 \uc219\uc81c\uac00 \uc788\uc73c\uba70, \uac01 \uc219\uc81c\uc5d0\ub294 $1$ \uc774\uc0c1 $N$ \uc774\ud558\uc758 \uace0\uc720 \ubc88\ud638\uac00 \ubd80\uc5ec\ub41c\ub2e4.<\/p>\r\n\r\n<p>\uc120\uc0dd\ub2d8\uc758 \uc219\uc81c \uacc4\ud68d\uc744 \ubcf4\uace0 \ubd84\ub178\ud55c \ud559\uc0dd\ub4e4\uc740 \uc120\uc0dd\ub2d8\uc5d0\uac8c \uc219\uc81c \uacc4\ud68d \uc694\uad6c\uc548\uc744 \uc81c\uc2dc\ud558\uc600\ub2e4.<\/p>\r\n\r\n<p>Mr Singh\uc740 \ud559\uc0dd\ub4e4\uc758 \uc694\uad6c\uc5d0 \uc751\ud558\uae30\ub85c \ud558\uba74\uc11c\ub3c4, \ucee4\ub9ac\ud058\ub7fc\uc744 \ub9dd\uce58\uace0 \uc2f6\uc9c0 \uc54a\uae30 \ub54c\ubb38\uc5d0, \ub2e4\uc74c \uc791\uc5c5\uc744 \uba87 \ubc88\uc774\ub4e0 \uc2e4\ud589\ud558\uc5ec \uc6d0\ub798 \uc219\uc81c \uacc4\ud68d\uc744 \uc694\uad6c\uc548\uc73c\ub85c \ubc14\uafc0 \uc218 \uc788\ub294\uc9c0 \ubcf4\uace0\uc790 \ud55c\ub2e4.<\/p>\r\n\r\n<ul>\r\n\t<li>$3$\uac1c\uc758 \uc778\uc811\ud55c \uc219\uc81c\ub97c \uc120\ud0dd\ud558\uc5ec \uc219\uc81c \ubc88\ud638\ub97c \uae30\uc900\uc73c\ub85c \uc624\ub984\ucc28\uc21c \ub610\ub294 \ub0b4\ub9bc\ucc28\uc21c\uc73c\ub85c \uc815\ub82c\ud55c\ub2e4.<\/li>\r\n<\/ul>\r\n\r\n<p>Mr Singh\uc774 \uc704 \uc791\uc5c5\uc744 \uba87 \ubc88\uc774\ub4e0 \ubc18\ubcf5\ud558\uc5ec \uc6d0\ub798 \uc219\uc81c \uacc4\ud68d\uc744 \uc694\uad6c\uc548\uc73c\ub85c \ubc14\uafc0 \uc218 \uc788\ub294\uc9c0 \uc870\uc0ac\ud558\ub294 \ud504\ub85c\uadf8\ub7a8\uc744 \uc791\uc131\ud558\uc2dc\uc624.<\/p>\r\n","input":"<p>\uc785\ub825\uc758 \uccab \ubc88\uc9f8 \uc904\uc5d0 $N$\uc774 \uc8fc\uc5b4\uc9c4\ub2e4.<\/p>\r\n\r\n<p>\uc785\ub825\uc758 \ub450 \ubc88\uc9f8 \uc904\uc5d0 \uc120\uc0dd\ub2d8\uc758 \uc6d0\ub798 \uc219\uc81c \uacc4\ud68d\uc774 \uc8fc\uc5b4\uc9c4\ub2e4. $N$\uac1c\uc758 \uc11c\ub85c \ub2e4\ub978 \uc815\uc218\uac00 \uacf5\ubc31\uc73c\ub85c \uad6c\ubd84\ub418\uc5b4 \uc8fc\uc5b4\uc9c0\uba70, \ubaa8\ub4e0 \uc815\uc218\ub294 $1$ \uc774\uc0c1 $N$ \uc774\ud558\uc774\ub2e4.<\/p>\r\n\r\n<p>\uc785\ub825\uc758 \uc138 \ubc88\uc9f8 \uc904\uc5d0 \ud559\uc0dd\ub4e4\uc774 \uc81c\uc2dc\ud55c \uc694\uad6c\uc548\uc774 \ub450 \ubc88\uc9f8 \uc904\uacfc \uac19\uc740 \ud615\uc2dd\uc73c\ub85c \uc8fc\uc5b4\uc9c4\ub2e4.<\/p>\r\n","output":"<p>\uccab \ubc88\uc9f8 \uc904\uc5d0 Mr Singh\uc774 \uc704 \uc791\uc5c5\uc744 \uba87 \ubc88\uc774\ub4e0 \uc2e4\ud589\ud558\uc5ec \uc6d0\ub798 \uc219\uc81c \uacc4\ud68d\uc744 \uc694\uad6c\uc548\uc73c\ub85c \ubc14\uafc0 \uc218 \uc788\ub294\uc9c0\ub97c \ucd9c\ub825\ud55c\ub2e4. \uac00\ub2a5\ud558\uba74 <code>POSSIBLE<\/code>\uc744, \ubd88\uac00\ub2a5\ud558\uba74 <code>IMPOSSIBLE<\/code>\uc744 \ucd9c\ub825\ud55c\ub2e4. \ub300\uc18c\ubb38\uc790\uc5d0 \uc720\uc758\ud55c\ub2e4.<\/p>\r\n","hint":"","original":"1","html_title":"0","problem_lang_tcode":"Korean","limit":"<ul>\r\n\t<li>$3 \\leq N \\leq 100\\,000$<\/li>\r\n<\/ul>\r\n","sample_explain_1":"<p>\ub2e4\uc74c\uacfc \uac19\uc740 \uacfc\uc815\uc744 \uac70\uccd0 \uc219\uc81c \uacc4\ud68d\uc744 \ubc14\uafc0 \uc218 \uc788\ub2e4.<\/p>\r\n\r\n<ul>\r\n\t<li>5 4 3 1 2<\/li>\r\n\t<li>3 4 5 1 2<\/li>\r\n\t<li>3 4 1 2 5<\/li>\r\n\t<li>3 1 2 4 5<\/li>\r\n\t<li>1 2 3 4 5<\/li>\r\n<\/ul>\r\n"},{"problem_id":"27894","problem_lang":"1","title":"Exceptional Homework Jargon","description":"<p>Mr Singh is a teacher at NLCS Jeju. He is currently planning a&nbsp;curriculum for his year 12 students, who are struggling with the IB diploma programme.<\/p>\r\n\r\n<p>He has created a homework plan, which is a sequence by which he should assign homework to students. His lesson plan consists of $N$ homework assignments, with each assignment being assigned a unique integer between $1$ and $N$ (inclusive).<\/p>\r\n\r\n<p>However, upon receiving the homework plan, students were angry about the workload, so they asked Mr Singh&nbsp;to rearrange the homework assignments according to their &#39;ideal&#39; homework plan.<\/p>\r\n\r\n<p>Although Mr Singh&nbsp;conceded to his students&#39; requests, he wanted to ensure that his curriculum remains coherent. Therefore, he is trying to convert his original homework plan into the proposed &#39;ideal&#39; plan, doing the following operation for any number of times:<\/p>\r\n\r\n<ul>\r\n\t<li>Choose three consecutive homework assignments, and sort their order (either in ascending or descending order).<\/li>\r\n<\/ul>\r\n\r\n<p>Write a program to help Mr Singh determine whether this is possible.<\/p>\r\n","input":"<p>In the first line of input, $N$ will be given.<\/p>\r\n\r\n<p>In the second line of input, his original lesson plan will be given. $N$ integers will be given, each separated by a space. All integers will be between $1$ and $N$ (inclusive).&nbsp;No integer will be given twice.<\/p>\r\n\r\n<p>In the third line of input, the proposed &#39;ideal&#39; lesson plan will be given, in the same format as the original lesson plan.<\/p>\r\n","output":"<p>In the first line of output, print whether it is possible for Mr Singh&nbsp;to transform the original plan into the &#39;ideal&#39; plan. If this is possible, print <code>POSSIBLE<\/code>. If this is impossible, print <code>IMPOSSIBLE<\/code>. Be aware of the capitalisation.<\/p>\r\n","hint":"","original":"0","html_title":"0","problem_lang_tcode":"English","limit":"<ul>\r\n\t<li>$3&nbsp;\\leq N \\leq 100\\,000$<\/li>\r\n<\/ul>\r\n","sample_explain_1":"<p>Following steps can be taken to convert the homework plan:<\/p>\r\n\r\n<ul>\r\n\t<li>5 4 3 1 2<\/li>\r\n\t<li>3 4 5 1 2<\/li>\r\n\t<li>3 4 1 2 5<\/li>\r\n\t<li>3 1 2 4 5<\/li>\r\n\t<li>1 2 3 4 5<\/li>\r\n<\/ul>\r\n"}]

출처

High School > NLCS Jeju > GEC-Cup G번