#include<bits/stdc++.h>
using namespace std;
inline int read()
{int x=0,f=1;char ch=getchar();while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}while(ch<='9'&&ch>='0'){x=x*10+ch-'0';ch=getchar();}return x*f;
}
int q[101000],a[101000],fa[101000],n,m,len=0,dd,lin[101000],cnt=0,p[100100][23],hash[101000],l[2500000],r[2500000],sum[2500000],d[101000],root[101000];
bool f[101000];
struct one
{int y,next;
};
one e[201000];
void insert(int xx,int yy)
{e[++len].next=lin[xx];lin[xx]=len;e[len].y=yy;
}
int maketree(int L,int R)
{int rt=++len;sum[rt]=0;if(L<R){int mid=(L+R)>>1;l[rt]=maketree(L,mid);r[rt]=maketree(mid+1,R);}return rt;
}
int lca(int x,int y)
{if(d[x]>d[y])swap(x,y);int ff=d[y]-d[x];for(int i=0;(1<<i)<=n;i++){if((1<<i)&ff)y=p[y][i];}if(x==y)return x;for(int i=log2(n);i>=0;i--)if(p[x][i]!=p[y][i]){x=p[x][i];y=p[y][i];}x=p[x][0];return x;
}
int update(int pre,int L,int R,int x)
{int rt=++len;sum[rt]=sum[pre]+1;l[rt]=l[pre];r[rt]=r[pre];if(L<R){int mid=(L+R)>>1;if(x<=mid)l[rt]=update(l[pre],L,mid,x);else r[rt]=update(r[pre],mid+1,R,x);}return rt;
}
void init()
{q[1]=1;int head=0,tail=1;f[1]=true;while(head++<tail){int tn=q[head];int x=lower_bound(hash+1,hash+dd+1,a[tn])-hash;root[tn]=update(root[fa[tn]],1,dd,x);for(int i=lin[tn];i;i=e[i].next){if(f[e[i].y])continue;f[e[i].y]=true;fa[e[i].y]=tn;p[e[i].y][0]=tn;d[e[i].y]=d[tn]+1;q[++tail]=e[i].y;}}for(int i=1;i<=22;i++){for(int j=1;j<=n;j++){p[j][i]=p[p[j][i-1]][i-1];}}
}int query(int x,int y,int LCA,int faLCA,int L,int R,int k)
{int f1=sum[l[x]]-sum[l[faLCA]]+sum[l[y]]-sum[l[LCA]];if(L>=R)return L;int mid=(L+R)>>1;if(k<=f1)return query(l[x],l[y],l[LCA],l[faLCA],L,mid,k);else return query(r[x],r[y],r[LCA],r[faLCA],mid+1,R,k-f1);
}
int work(int x,int y,int k)
{int LCA=lca(x,y);return query(root[x],root[y],root[LCA],root[fa[LCA]],1,dd,k);
}
int main()
{//freopen("xf.in","r",stdin);//freopen("xf.out","w",stdout);n=read();m=read();int x,y,k;for(int i=1;i<=n;i++){scanf("%d",&a[i]);hash[i]=a[i];}for(int i=1;i<n;i++){x=read();y=read();insert(x,y);insert(y,x);}len=0;sort(hash+1,hash+n+1);dd=unique(hash+1,hash+n+1)-hash-1;root[0]=maketree(1,dd);init();int ans=0;for(int i=1;i<m;i++){x=read();x^=ans;y=read();k=read();ans=hash[work(x,y,k)];printf("%d\n",ans);}x=read();x^=ans;y=read();k=read();ans=hash[work(x,y,k)];printf("%d",ans);return 0;
}