#include<iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<vector>

 #define lson l,m

 #define rson m+1,r

 using namespace std;

 const int MAXN=+;

 const int DEG=;

 int w[MAXN];

 vector<int> E[MAXN];

 int d,hash[MAXN];

 int T[MAXN],tot,sum[MAXN<<],L[MAXN<<],R[MAXN<<];

 int anc[MAXN][DEG],dep[MAXN];

 int n,m;

 /*Chairman Tree*/

 int build(int l,int r)

 {

     int rt=++tot;

     sum[rt]=;

     if (l!=r)

     {

         int m=(l+r)>>;

         L[rt]=build(lson);

         R[rt]=build(rson);

     }

     return rt;

 }

 int update(int pre,int l,int r,int x)

 {

     int rt=++tot;

     L[rt]=L[pre],R[rt]=R[pre];

     sum[rt]=sum[pre]+;

     if (l!=r)

     {

         int m=(l+r)>>;

         if (x<=m) L[rt]=update(L[pre],lson,x);

             else R[rt]=update(R[pre],rson,x);

     }

     return rt;

 }

 int query(int u,int v,int lca,int lcafa,int l,int r,int k)

 {

     if (l==r) return l;

     int num=(sum[L[u]]-sum[L[lca]]+sum[L[v]]-sum[L[lcafa]]);

     int m=(l+r)>>;

     if (num>=k) return query(L[u],L[v],L[lca],L[lcafa],lson,k);

         else return query(R[u],R[v],R[lca],R[lcafa],rson,k-num);

 }

 /*LCA*/

 void getanc()

 {

     for (int i=;i<DEG;i++)

         for (int j=;j<=n;j++)

             anc[j][i]=anc[anc[j][i-]][i-];

 }

 int swim(int x,int H)

 {

     for (int i=;H>;i++)

     {

         if (H&) x=anc[x][i];

         H>>=;

     }

     return x;

 }

 int LCA(int u,int v)

 {

     if (dep[u]<dep[v]) swap(u,v);

     u=swim(u,dep[u]-dep[v]);

     if (u==v) return u;

     for (int i=DEG-;i>=;i--)

     {

         if (anc[u][i]!=anc[v][i])

         {

             u=anc[u][i];

             v=anc[v][i];

         }

     }

     return anc[u][];

 }

 /*main*/

 void dfs(int u,int pa,int depth)

 {

     anc[u][]=pa;

     dep[u]=depth;

     int x=lower_bound(hash+,hash+d+,w[u])-hash;

     T[u]=update(T[pa],,d,x);

     for (int i=;i<E[u].size();i++)

         if (E[u][i]!=pa) dfs(E[u][i],u,depth+);

 }

 void init()

 {

     scanf("%d%d",&n,&m);

     for (int i=;i<=n;i++) scanf("%d",&w[i]),hash[i]=w[i];

     sort(hash+,hash+n+);

     d=unique(hash+,hash+n+)-(hash+);

     for (int i=;i<n;i++)

     {

         int u,v;

         scanf("%d%d",&u,&v);

         E[u].push_back(v);

         E[v].push_back(u);

     }

     tot=;

     T[]=build(,d);//对于根先建立主席树

 }

 void solve()

 {

     getanc();

     int preans=;

     for (int i=;i<m;i++)

     {

         int u,v,k;

         scanf("%d%d%d",&u,&v,&k);

         u=u^preans;

         int lca=LCA(u,v);

         int ans=query(T[u],T[v],T[lca],T[anc[lca][]],,d,k);

         printf("%d",hash[ans]);

         if (i!=m-) printf("\n");

         preans=hash[ans];

     }

 }

 int main()

 {

     init();

     dfs(,,);

     solve();

     return ;

 }