Give you a binary
tree **T**. Please print the level
traversal of **T**.

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Give you a binary
tree **T**. Please print the level
traversal of **T**.

First line is an integer T, which is the number of test cases. (1 <= T <= 50)

For each test case, there will be an integer in a single line N (1 <= N <= 1024). N is the number of nodes. The nodes are numbered from 1 to N.

Then there will be N – 1 lines with two integer x, y for each line. (1 <= x, y <= N)

x y means x is the farther of y. What’s more, we guarantee the input file is a tree. And the child appears first is the left child, the other one appears later is right child.

For each test case, print the level traversal of the tree in a single line.

```
1
8
1 4
1 3
4 2
2 7
3 5
3 6
6 8
```

```
1 4 3 2 5 6 7 8
```

Easy problem.