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QOJ

Time Limit: 2 s Memory Limit: 512 MB Total points: 100

#18806. 树与查询 3

Statistics

有一棵由 $N$ 个顶点构成的树(无向无环连通图)。顶点编号为 $1$ 到 $N$,边编号为 $1$ 到 $N-1$。最初,所有顶点的颜色均为白色。

请编写一个程序处理以下两种查询:

  • 1 i:改变第 $i$ 个顶点的颜色(白色 $\to$ 黑色,黑色 $\to$ 白色)。
  • 2 v:输出从顶点 $1$ 到顶点 $v$ 的路径上第一个黑色顶点的编号。若不存在这样的顶点,则输出 $-1$。

输入格式

第一行给出 $N$($2 \le N \le 100{,}000$)。

接下来 $N-1$ 行,每行给出第 $i$ 条边所连接的两个顶点编号 $u$ 和 $v$。

接下来一行给出查询的个数 $M$($1 \le M \le 100{,}000$)。

接下来 $M$ 行,每行给出一个查询。

输出格式

对于每个 $2$ 号查询,按顺序每行输出一个结果。

样例

样例输入 1

9
1 2
1 3
2 4
2 9
5 9
7 9
8 9
6 8
8
2 3
1 8
2 6
2 7
1 2
2 9
1 2
2 9

样例输出 1

-1
8
-1
2
-1

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