[BOJ 11623] Kernel Knights

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Points: 4
Time limit: 2.0s
Memory limit: 512M

Problem types
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Assembly, Awk, C, C++, Java, Pascal, Perl, Python, Sed, Text

Jousting is a medieval contest that involves people on horseback trying to strike each other with wooden lances while riding at high speed. A total of 2n knights have entered a jousting tournament – n knights from each of the two great rival houses. Upon arrival, each knight has challenged a single knight from the other house to a duel.</p>

A kernel is defined as some subset S of knights with the following two properties:

  • No knight in S was challenged by another knight in S.
  • Every knight not in S was challenged by some knight in S.

Given the set of the challenges issued, find one kernel. It is guaranteed that a kernel always exists.

입력 형식

The first line contains an integer n (1 ≤ n ≤ 100 000) – the number of knights of each house. The knights from the first house are denoted with integers 1 through n, knights from the second house with integers n + 1 through 2n.</p>

The following line contains integers f1, f2, . . . , fn – the k-th integer fk is the index of the knight challenged by knight k (n + 1 ≤ fk ≤ 2n).

The following line contains integers s1,s2, . . . ,sn – the k-th integer sk is the index of the knight challenged by knight n + k (1 ≤ sk ≤ n).

출력 형식

Output the indices of the knights in the kernel on a single line. If there is more than one solution, you may output any one.

예제 입력

4
5 6 7 7
1 3 2 3

예제 출력

1 2 4 8

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