#include<bits/stdc++.h>
using namespace std;
#define N ((1<<17)-1)int n,m,rv[N],v[N],dep[N],jp[N][20],cnt,p[N];
bool vis[N];
vector<vector<int> >G;struct SN{SN *son[2];int val;
}sn[N*20],*root[N];void build(SN&x,int l,int r)
{if (l==r) return;int m=(l+r)>>1;x.son[0]=&sn[++cnt];x.son[1]=&sn[++cnt];build(*x.son[0],l,m);build(*x.son[1],m+1,r);
}inline bool cmp(int a,int b){return rv[a]<rv[b];}void putin()
{int i,x,y;scanf("%d%d",&n,&m);G.resize(n+1);for (i=1;i<=n;i++) scanf("%d",&rv[i]),p[i-1]=i;sort(p,p+n,cmp);for (i=0;i<n;i++) v[p[i]]=i;for (i=0;i<n-1;i++){scanf("%d%d",&x,&y);G[x].push_back(y);G[y].push_back(x);}build(sn[0],0,n-1);root[0]=&sn[0];
}void rebuild(SN&x,int l,int r,int k)
{x.val++;if (l==r) return;int m=(l+r)>>1,s;if (k<=m) s=0,r=m;else s=1,l=m+1;sn[++cnt]=*x.son[s];x.son[s]=&sn[cnt];rebuild(*x.son[s],l,r,k);
}void dfs(int x,int f,int d)
{int i;vis[x]=1;dep[x]=d;jp[x][0]=f;for (i=0;jp[x][i];i++)jp[x][i+1]=jp[jp[x][i]][i];root[x]=&sn[++cnt];*root[x]=*root[f];rebuild(*root[x],0,n-1,v[x]);for (i=0;i<G[x].size();i++)if (!vis[G[x][i]]) dfs(G[x][i],x,d+1);
}int search(SN&a,SN&b,SN&c,SN&d,int l,int r,int k)
{if (l==r) return l;int val=(*a.son[0]).val+(*b.son[0]).val-(*c.son[0]).val-(*d.son[0]).val;int m=(l+r)>>1,s;if (val>=k) s=0,r=m;else s=1,k-=val,l=m+1;return search(*a.son[s],*b.son[s],*c.son[s],*d.son[s],l,r,k);
}int LCA(int u,int v)
{int i;if (dep[u]!=dep[v]){if (dep[u]<dep[v]) swap(u,v);for (i=17;i>=0;i--)if (dep[u]-(1<<i)>=dep[v])u=jp[u][i];}if (u==v) return u;for (i=17;i>=0;i--)if (jp[u][i]!=jp[v][i]) {u=jp[u][i];v=jp[v][i];}return jp[u][0];
}void answer()
{int i,ans=0,u,v,k,lca;for (i=0;i<m;i++){scanf("%d%d%d",&u,&v,&k);u^=ans;lca=LCA(u,v);ans=rv[p[search(*root[u],*root[v],*root[lca],*root[jp[lca][0]],0,n-1,k)]];printf("%d",ans);if (i<m-1) printf("\n");}
}int main()
{putin();dfs(1,0,1);answer();
}