I see a pink boar and I want it painted black. Black boars look much more awesome and mighty than the pink ones. Since Jaggy became the ruler of the forest, he has been trying his best to improve the diplomatic relations between the forest region and the nearby ones.
Some other rulers, however, have requested too much in return for peace between their two regions, so he realized he has to resort to intimidation. Once a delegate for diplomatic relations of a neighboring region visits Jaggy's forest, if they see a whole bunch of black boars, they might suddenly change their mind about attacking Jaggy. Black boars are really scary, after all.
Jaggy's forest can be represented as a tree (graph without cycles) with
Since Jaggy is too busy to plan the squirrel's route, he needs your help. He wants you to construct a walk through the tree starting from vertex
Input Specification
The first line of input contains the integer
If the
, then the corresponding node is black , then the node is pink
Each of the next
Output Specification
Output the path of a squirrel: output a sequence of visited nodes' indices in order of visiting. In case all of the nodes are initially black you should print
Constraints
Sample Input
5
1
1
-1
1
-1
2 5
4 3
2 4
4 1
Sample Output
1 4 2 5 2 4 3
Explanation
At the beginning squirrel is at node 1 and its color is black. Next steps are as follows:
- From node 1 we walk to node 4 and change its color to pink
- From node 4 we walk to node 2 and change its color to pink
- From node 2 we walk to node 5 and change its color to black
- From node 5 we return to node 2 and change its color to black
- From node 2 we walk to node 4 and change its color to black
- Finally, we visit node 3 and change its color to black
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