#include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<cmath>

 #include<iostream>

 #include<vector>

 using namespace std;

 #define LL long long

 const int maxn=;

 const int maxm=;

 int n,m;

 int a[maxn]={},fa[maxn][]={},dep[maxn]={},rt[maxn]={};

 int sig[maxm][]={},sz[maxm]={},cnt=;

 struct nod{int y,next;}e[maxn*];int head[maxn],tot=;

 inline void init(int x,int y){e[++tot].y=y;e[tot].next=head[x];head[x]=tot;}

 inline int getnew(){

     sig[++cnt][]=;sig[cnt][]=;

     sz[cnt]=;return cnt;

 }

 inline void bui(int x,int pa,int val){

     rt[x]=getnew();pa=rt[pa];

     x=rt[x];

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

         int ch=(val>>i)&;

         if(!sig[x][ch]){

             int id=getnew();

             sig[x][ch]=id; sig[x][!ch]=sig[pa][!ch];

             sz[sig[x][ch]]=sz[sig[pa][ch]];

         }

         x=sig[x][ch];pa=sig[pa][ch];

         ++sz[x];

     }

 }

 void dfs(int x){

     bui(x,fa[x][],a[x]);

     for(int i=;fa[x][i-];++i)fa[x][i]=fa[fa[x][i-]][i-];

     for(int i=head[x];i;i=e[i].next){

         if(e[i].y==fa[x][])continue;

         fa[e[i].y][]=x;dep[e[i].y]=dep[x]+;dfs(e[i].y);

     }

 }

 inline int getlca(int x,int y){

     if(dep[x]<dep[y])swap(x,y);

     for(int i=;i>=;--i)if(dep[fa[x][i]]>=dep[y])x=fa[x][i];

     if(x==y)return x;

     for(int i=;i>=;--i)if(fa[x][i]!=fa[y][i]){x=fa[x][i];y=fa[y][i];}

     return fa[x][];

 }

 int Query(int x,int y,int val){

     int lc=getlca(x,y); int res=a[lc]^val;

     x=rt[x];y=rt[y];lc=rt[lc];

     int ret=;

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

         int ch=(val>>i)&;

         if(sz[sig[x][!ch]]+sz[sig[y][!ch]]-*sz[sig[lc][!ch]]>){

             ret+=<<i;

             ch=!ch;

         }

         x=sig[x][ch];y=sig[y][ch];lc=sig[lc][ch];

     }

     return max(res,ret);

 }

 int main(){

     while(~scanf("%d%d",&n,&m)){

         memset(head,,sizeof(head));memset(rt,,sizeof(rt));

         memset(sig,,sizeof(sig));memset(fa,,sizeof(fa));

         int x,y,z;tot=;cnt=;

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

         for(int i=;i<n;i++){scanf("%d%d",&x,&y);init(x,y);init(y,x);}

         dep[]=;dfs();

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

             scanf("%d%d%d",&x,&y,&z);

             printf("%d\n",Query(x,y,z));

         }

     }

     return ;

 }