COCI '19 Contest 2 #2 Slagalica

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Points: 10 (partial)
Time limit: 1.0s
Memory limit: 512M

Problem type

Little Fabian got a one-dimensional jigsaw puzzle that consists of N pieces. He quickly realized that each piece belongs to one of the following types:

Additionally, it is known that among those N pieces there is exactly one piece of either type 5 or type 6 (left border) and exactly one piece of either type 7 or type 8 (right border).

Fabian wishes to arrange all of the pieces into a single row such that the first (leftmost) piece is of type 5 or 6 and the last (rightmost) piece is of type 7 or 8. Two pieces can be placed next to each other if and only if their neighbouring borders are of different shapes, i.e., one has a bump (also called outie or tab) and the other has a hole (also called innie or blank).

Simply solving the puzzle would be too easy for Fabian so he decided to write a unique positive integer on each of the pieces. Now he is interested in finding the lexicographically smallest solution to the jigsaw puzzle. The solution A is considered lexicographically smaller than solution B if at the first position (from the left) i where they differ it holds that the number written on i-th puzzle in A is smaller than the number written on i-th puzzle in B.

Note: the pieces cannot be rotated.

Input

The first line contains an integer N (2 \le N \le 10^5) from the task description.

The next N lines contain two integers X_i (1 \le X_i \le 8) and A_i (1 \le A_i \le 10^9) which represent the type of the i-th piece and the number Fabian wrote on it. All numbers A_i will be different.

Output

If Fabian cannot solve the jigsaw puzzle, you should output -1 in a single line.

Otherwise, you should output the numbers that are written on the pieces in the lexicographically smallest solution to the puzzle.

Scoring

In test cases worth a total of 5 points it will hold N \le 4.
In test cases worth additional 5 points it will hold N \le 10.
In test cases worth additional 10 points pieces of types 2 and 3 will not appear in the input.
In test cases worth additional 20 points there will be at most one piece of type 1 or 4.

If for some test case in which the solution to the puzzle exists, you output the correctly solved puzzle but your solution is not lexicographically smallest, you will get 40\% of the points intended for that test case.

Sample Input 1

5
1 5
2 7
2 3
8 4
6 1

Sample Output 1

1 3 7 5 4

Explanation For Sample 1

There are only two possible solutions to the puzzle:

We can see that the second depicted solution has a smaller number written on the second piece. Therefore, that is the lexicographically smallest solution.

Sample Input 2

3
5 1
7 2
4 3

Sample Output 2

1 3 2

Sample Input 3

5
2 5
2 7
2 3
8 4
6 1

Sample Output 3

-1

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