#include <stdio.h>

#include <string.h>

#include <algorithm>

using namespace std;

#define N 100050

int head[N],to[N<<1],nxt[N<<1];

int top[N],fa[N],dep[N],son[N],siz[N],tot,cnt;

int n,m,root[N],t[N*50],ls[N*50],rs[N*50],a[N],see;

struct A{

	int num,id,v;

}d[N];

bool cmp1(const A &x,const A &y){return x.num<y.num;}

bool cmp2(const A &x,const A &y){return x.id<y.id;}

inline void add(int u,int v){

	to[++cnt]=v;nxt[cnt]=head[u];head[u]=cnt;

}

void rd(int &x){

	int f=1;x=0;char s=getchar();

	while(s<'0'||s>'9'){if(s=='-')f=-1;s=getchar();}

	while(s>='0'&&s<='9'){x=x*10+s-'0';s=getchar();}x*=f;

}

void dfs1(int x){

	siz[x]=1;

	for(int i=head[x];i;i=nxt[i])if(to[i]!=fa[x]){

		fa[to[i]]=x;dep[to[i]]=dep[x]+1;

		dfs1(to[i]);

		siz[x]+=siz[to[i]];

		if(siz[to[i]]>siz[son[x]])son[x]=to[i];

	}

}

void dfs2(int x,int t){

	top[x]=t;

	if(son[x])dfs2(son[x],t);

	for(int i=head[x];i;i=nxt[i])if(to[i]!=fa[x]&&to[i]!=son[x])dfs2(to[i],to[i]);

}

int LCA(int x,int y){

	while(top[x]!=top[y]){

		if(dep[top[x]]>dep[top[y]])swap(x,y);

		y=fa[top[y]];

	}

	return dep[x]<dep[y]?x:y;

}

void insert(int x,int &y,int l,int r,int val){

	y=++tot;

	if(l==r){t[y]=t[x]+1;return ;}

	int mid=l+r>>1;

	if(val<=mid) rs[y]=rs[x],insert(ls[x],ls[y],l,mid,val);

	else ls[y]=ls[x],insert(rs[x],rs[y],mid+1,r,val);

	t[y]=t[ls[y]]+t[rs[y]];

}

int query(int x,int y,int lca,int f,int l,int r,int k){

	if(l==r)return a[l];

	int mid=l+r>>1,sizls=t[ls[x]]+t[ls[y]]-t[ls[lca]]-t[ls[f]];

	if(k<=sizls) return query(ls[x],ls[y],ls[lca],ls[f],l,mid,k);

	else return query(rs[x],rs[y],rs[lca],rs[f],mid+1,r,k-sizls);

}

void build(int x){

	for(int i=head[x];i;i=nxt[i]){

		if(to[i]!=fa[x]){

			insert(root[x],root[to[i]],1,n,d[to[i]].v);

			build(to[i]);

		}

	}

}

int main(){

	rd(n);rd(m);

	int i,x,y,k,j;

	for(i=1;i<=n;i++) rd(d[i].num),d[i].id=i;

	sort(d+1,d+n+1,cmp1);

	d[0].num=-1000000;

	for(j=0,i=1;i<=n;i++){if(d[i].num!=d[i-1].num)j++;d[i].v=j;a[j]=d[i].num;}

	sort(d+1,d+n+1,cmp2);

	for(i=1;i<n;i++) {

		rd(x);rd(y);

		add(x,y);add(y,x);

	}

	dep[1]=1;fa[1]=0;

	dfs1(1);dfs2(1,1);

	int ans=0;

	//for(i=1;i<=n;i++) insert(root[fa[a[i]]],root[a[i]],minn,maxn,v[a[i]]);

	insert(root[0],root[1],1,n,d[1].v);

	build(1);

	for(i=1;i<=m;i++) {

		scanf("%d%d%d",&x,&y,&k);x^=ans;

		int lca=LCA(x,y);

		ans=query(root[x],root[y],root[lca],root[fa[lca]],1,n,k);

		if(i<m)

		printf("%d\n",ans);

		else printf("%d",ans);

	}

}