1 #include <cstdio>
 2 #include <cstring>
 3 #include <algorithm>
 4 #include <iostream>
 5 #define N 100005
 6 using namespace std;
 7 
 8 
 9 struct node{
10     int l, r;
11     int dis;
12     int val;
13     int f;
14 }tree[N];
15 
16 int findroot(int p);
17 int merge(int x,int y);
18 int del(int x);
19 void solve(int x,int y);
20 
21 
22 main()
23 {
24     int n, m, i, j, k;
25     while(scanf("%d",&n)==1){
26         for(i=1;i<=n;i++){
27             scanf("%d",&tree[i].val);
28             tree[i].l=tree[i].r=tree[i].dis=0;
29             tree[i].f=i;
30         }
31         int x, y;
32         scanf("%d",&m);
33         while(m--){
34             scanf("%d %d",&x,&y);
35             int fx=findroot(x);
36             int fy=findroot(y);
37             if(fx==fy){
38                 printf("-1\n");
39                 continue;
40             }
41             solve(fx,fy);
42         }
43     }
44 }
45 
46 int findroot(int p){
47     int r=p;
48     while(r!=tree[r].f){
49         r=tree[r].f;
50     }
51     return r;
52 }
53 
54 int merge(int x,int y){
55     if(x==0) return y;
56     if(y==0) return x;
57     if(tree[x].val<tree[y].val) swap(x,y);
58     tree[x].r=merge(tree[x].r,y);
59     tree[tree[x].r].f=x;
60     if(tree[tree[x].r].dis>tree[tree[x].l].dis) swap(tree[x].l,tree[x].r);
61     if(!tree[x].r) tree[x].dis=0;
62     else tree[x].dis=tree[tree[x].r].dis+1;
63     return x;
64 }
65 
66 int del(int x){
67     int left=tree[x].l;
68     int right=tree[x].r;
69     tree[left].f=left;
70     tree[right].f=right;
71     tree[x].l=tree[x].r=tree[x].dis=0;
72     return merge(left,right);
73 }
74 
75 void solve(int x,int y){
76     tree[x].val/=2;
77     tree[y].val/=2;
78     int left=del(x);
79     int right=del(y);
80     left=merge(left,x);
81     right=merge(right,y);
82     int num=merge(left,right);
83     printf("%d\n",tree[num].val);
84 }