题目描述
Hossam gives you a sequence of integers $a_1, \, a_2, \, \dots, \, a_n$ of length $n$. Moreover, he will give you $q$ queries of type $(l, \, r)$. For each query, consider the elements $a_l, \, a_{l + 1}, \, \dots, \, a_r$. Hossam wants to know the smallest number in this sequence, such that it occurs in this sequence an odd number of times.
You need to compute the answer for each query before process the next query.
Input
The first line of the input contains one integer $n$ ($1 \le n \le 2 \cdot 10^5$), the length of the sequence.
The second line contains $n$ integers $a_1, \, a_2, \, \dots, \, a_n$ ($1 \le a_i \le 10^9$).
The third line contains one integer $q$ ($1 \le q \le 2 \cdot 10^5$), the number of queries.
Each of the next $q$ lines contains two integers $a$ and $b$ ($0 \le a, \, b \le 2 \cdot 10^9$), the numbers used to encode the queries.
Let $\mathrm{ans}_i$ be the answer on the $i$-th query, and $\mathrm{ans}_0$ be zero. Then $$l_i = a_i \oplus \mathrm{ans}_{i - 1},$$ $$r_i = b_i \oplus \mathrm{ans}_{i - 1},$$ where $l_i, \, r_i$ are parameters of the $i$-th query and $\oplus$ means the bitwise exclusive or operation. It is guaranteed that $1 \le l \le r \le n$.
Output
For each query, print the smallest number that occurs an odd number of times on the given segment of the sequence.
If there is no such number, print $0$.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
样例输出
提示
In the example,
$$l_1 = 1, \, r_1 = 2,$$ $$l_2 = 1, \, r_2 = 3,$$ $$l_3 = 2, \, r_3 = 4,$$ $$l_4 = 1, \, r_4 = 4,$$ $$l_5 = 2, \, r_5 = 2,$$ $$l_6 = 1, \, r_6 = 5.$$