TDMU

#### Start

2018-01-08 13:00 CET

## TDMU

#### End

2018-01-15 13:00 CET
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# Problem HKitten on a Tree

Ouch! A kitten got stuck on a tree. Fortunately, the tree’s branches are numbered. Given a description of a tree and the position of the kitten, can you write a program to help the kitten down?

## Input

The input is a description of a single tree. The first line contains an integer $K$, denoting the branch on which the kitten got stuck. The next lines each contain two or more integers $a, b_1, b_2, \ldots$. Each such line denotes a branching: the kitten can reach $a$ from $b_1, b_2, \ldots$ on its way down. Thus, $a$ will be closer to the root than any of the $b_ i$. The description ends with a line containing -1. Each branch $b_ i$ will appear on exactly one line. All branch numbers are in the range $1..100$, though not necessarily contiguous. You are guaranteed that there is a path from every listed branch to the root. The kitten will sit on a branch that has a number that is different than the root.

The illustration above corresponds to the sample input.

## Output

Output the path to the ground, starting with the branch on which the kitten sits.

Sample Input 1 Sample Output 1
14
25 24
4 3 1 2
13 9 4 11
10 20 8 7
32 10 21
23 13 19 32 22
19 12 5 14 17 30
14 6 15 16
30 18 31 29
24 23 26
26 27 28
-1

14 19 23 24 25