1 //HDOJ 1512
 2 #include<vector>
 3 #include<cstdio>
 4 #include<cstring>
 5 #include<cstdlib>
 6 #include<iostream>
 7 #include<algorithm>
 8 #define rep(i,n) for(int i=0;i<n;++i)
 9 #define F(i,j,n) for(int i=j;i<=n;++i)
10 #define D(i,j,n) for(int i=j;i>=n;--i)
11 #define pb push_back
12 using namespace std;
13 inline int getint(){
14     int v=0,sign=1; char ch=getchar();
15     while(ch<‘0‘||ch>‘9‘){ if (ch==‘-‘) sign=-1; ch=getchar();}
16     while(ch>=‘0‘&&ch<=‘9‘){ v=v*10+ch-‘0‘; ch=getchar();}
17     return v*sign;
18 }
19 const int N=1e6+10,INF=~0u>>2;
20 typedef long long LL;
21 /******************tamplate*********************/
22 int n,m;
23 struct node{
24     int v,l,r,dis,f;
25     node(int v=0,int l=0,int r=0,int dis=0,int f=0):
26         v(v),l(l),r(r),dis(dis),f(f){}
27     void out(){
28         printf("%d %d %d %d %d\n",v,l,r,dis,f);
29     }
30 };
31 struct Left_tree{
32     node t[N];
33     int merge(int x,int y){
34         if (x==0) return y;
35         if (y==0) return x;
36         if (t[x].v<t[y].v) swap(x,y);
37         t[x].r=merge(t[x].r,y);
38         t[t[x].r].f=x;
39         if (t[t[x].l].dis<t[t[x].r].dis) swap(t[x].l,t[x].r);
40         if (t[x].r==0) t[x].dis=0;
41         else t[x].dis=t[t[x].r].dis+1;
42         return x;
43     }
44     int pop(int x){
45         int l=t[x].l,r=t[x].r;
46         t[l].f=l; t[r].f=r;
47         t[x].l=t[x].r=t[x].dis=0;
48         return merge(l,r);
49     }
50     int find(int x){return t[x].f==x ? x : find(t[x].f);}
51     void init(){
52         int x=0;
53         F(i,1,n){
54             x=getint();
55             t[i]=node(x);
56             t[i].f=i;
57         }
58     }
59     void solve(){
60         m=getint();
61         int x,y;
62         F(i,1,m){
63             x=getint(); y=getint();
64             int f1=find(x),f2=find(y);
65             if (f1==f2){puts("-1");continue;}
66             int t1=pop(f1),t2=pop(f2);
67             t[f1].v/=2; t1=merge(t1,f1);
68             t[f2].v/=2; t2=merge(t2,f2);
69             t1=merge(t1,t2);
70             printf("%d\n",t[t1].v);
71         }
72     }
73 }heap;
74 int main(){
75 #ifndef ONLINE_JUDGE
76     freopen("1512.in","r",stdin);
77     freopen("1512.out","w",stdout);
78 #endif
79     while(scanf("%d",&n)!=EOF){
80         heap.init(); heap.solve();
81     }
82     return 0;
83 }