1 #include<cstdio>
 2 #include<algorithm>
 3 #define N 100010
 4 #define rg register
 5 #define ls (a[u].l)
 6 #define rs (a[u].r)
 7 using namespace std;
 8 int n,n2,m,tot,root[N],last[N],dep[N],top[N],hvy[N],fa[N],size[N],val[N],b[N];
 9 struct tree{
10     int sum,l,r;
11 }a[N*80];
12 struct edge{
13     int to,pre;
14 }e[N<<1];
15 inline int read(){
16     int k=0,f=1; char c=getchar();
17     while(c<'0'||c>'9')c=='-'&&(f=-1),c=getchar();
18     while('0'<=c&&c<='9')k=k*10+c-'0',c=getchar();
19     return k*f;
20 }
21 inline int qlca(int x,int y){
22     int f1=top[x],f2=top[y];
23     while(f1!=f2){
24         if(dep[f1]<dep[f2]) swap(x,y),swap(f1,f2);
25         x=fa[f1]; f1=top[x];
26     }
27     return dep[x]<dep[y]?x:y;
28 }
29 void update(int &u,int l,int r,int pos){
30     a[++tot]=a[u]; a[u=tot].sum++;
31     if(l==r) return;
32     int mid=(l+r)>>1;
33     if(pos<=mid) update(ls,l,mid,pos);
34     else update(rs,mid+1,r,pos);
35 }
36 int query(int u,int v,int lca,int f,int l,int r,int k){
37     if(l==r) return l;
38     int tmp=a[ls].sum+a[a[v].l].sum-a[a[lca].l].sum-a[a[f].l].sum,mid=(l+r)>>1;
39     return k<=tmp?query(ls,a[v].l,a[lca].l,a[f].l,l,mid,k):query(rs,a[v].r,a[lca].r,a[f].r,mid+1,r,k-tmp);
40 }
41 void dfs1(int x){
42     size[x]=1; dep[x]=dep[fa[x]]+1;
43     root[x]=root[fa[x]]; update(root[x],1,n2,val[x]);
44     for(rg int i=last[x],to;i;i=e[i].pre)if((to=e[i].to)!=fa[x]){
45         fa[to]=x; dfs1(to);
46         size[x]+=size[to];
47         if(size[to]>size[hvy[x]]) hvy[x]=to;
48     }
49 }
50 void dfs2(int x,int tp){
51     top[x]=tp;
52     if(hvy[x]) dfs2(hvy[x],tp);
53     for(rg int i=last[x],to;i;i=e[i].pre)
54         if((to=e[i].to)!=fa[x]&&to!=hvy[x]) dfs2(to,to);
55 }
56 int main(){
57     n=read(); m=read();
58     for(rg int i=1;i<=n;i++) val[i]=b[i]=read();
59     sort(b+1,b+1+n); n2=unique(b+1,b+1+n)-b-1;
60     for(rg int i=1;i<=n;i++) val[i]=lower_bound(b+1,b+1+n2,val[i])-b;
61     for(rg int i=1;i<n;i++){
62         int u=read(),v=read();
63         e[++tot]=(edge){v,last[u]}; last[u]=tot;
64         e[++tot]=(edge){u,last[v]}; last[v]=tot;
65     }
66     tot=0; dfs1(1); dfs2(1,1);
67     int last=0;
68     while(m--){
69         int u=read()^last,v=read(),k=read(),l=qlca(u,v),f=fa[l];
70         printf("%d\n",last=b[query(root[u],root[v],root[l],root[f],1,n2,k)]);
71     }
72     return 0;
73 }