#include<bits/stdc++.h>

#define us unsigned short
#define ll long long
const int N=20010,M=200010;

int n,m,i,x,y;
ll a[N];
int t[N];
struct edge
{
    int to,next;
}l[N+M<<1];int e;
int qt[N];
ll ans[M];bool have[M];

bool vis[N];
us q[N],head,tail;
namespace kcz
{
us sz[N],f[N];
us get_g(int x)
{
    q[tail=1]=x;f[x]=0;
    for(head=1;head<=tail;++head)
    {
        x=q[head];sz[x]=1;
        for(i=t[x];y=l[i].to;i=l[i].next) 
        if(!vis[y]&&y!=f[x])
        {
            f[y]=x;
            q[++tail]=y;
        }
    }
    for(head=tail;head;--head)
    {
        x=q[head];
      if(sz[x]>=(tail>>1)) return x;
        sz[f[x]]+=sz[x];
    }
}
};
us belong[N];
ll g[61],f[N][61];

void ins(ll *f,ll x)
{
    short i; 
    for(i=60;x;--i) 
    if((x>>i)&1) 
     if(!f[i]){f[i]=x;return ;}
     else x^=f[i];
}
ll qiu(ll *f)
{
    ll ans=0;
    for(short i=60;i>=0;--i)
    if((ans^f[i])>ans) ans^=f[i];
    return ans;
}
us now;
void dfs(us x,us fr)
{
    belong[x]=now;
    int i;us y;
    for(i=0;i<=60;++i) f[x][i]=f[fr][i];
    ins(f[x],a[x]);
    for(i=t[x];y=l[i].to;i=l[i].next)
    if(y!=fr&&!vis[y]) dfs(y,x);
}
void merge(ll *g,ll *f1,ll *f2)
{
    int i;
    for(i=0;i<=60;++i) g[i]=f1[i];
    for(i=0;i<=60;++i) ins(g,f2[i]);
}
void solve(int x)
{
    vis[x]=1;
    belong[x]=0;
    for(i=0;i<=60;++i) f[x][i]=0;
    ins(f[x],a[x]);
    for(i=t[x];now=l[i].to;i=l[i].next) dfs(now,x);
    for(head=1;head<=tail;++head) 
    {
        x=q[head];
        for(i=qt[x];y=l[i].to;i=l[i].next)
        if(!have[i>>1]&&belong[x]!=belong[y])
        {
            have[i>>1]=1;
            merge(g,f[x],f[y]);
            ans[i>>1]=qiu(g);
        }
    } 
}

#define ch_top 10000000
char ch[ch_top],*now_r=ch,*now_w=ch-1;
void read(int &x)
{
    while(*now_r<'0') ++now_r;
    for(x=*now_r-'0';*++now_r>='0';) x=(x<<1)+(x<<3)+*now_r-'0';
}
void read(ll &x)
{
    while(*now_r<'0') ++now_r;
    for(x=*now_r-'0';*++now_r>='0';) x=(x<<1)+(x<<3)+*now_r-'0';
}
void write(ll &x)
{
    static us st[30],top;
    if(!x) *++now_w='0';
    else
    {
        for(;x;x/=10) st[++top]=x%10;
        for(;top;--top) *++now_w='0'+st[top];
    }
    *++now_w='\n';
}

int main()
{ freopen("1.in","r",stdin);freopen("1.out","w",stdout);
    fread(ch,1,ch_top,stdin);
    read(n);read(m);
    int i;
    for(i=1;i<=n;++i) read(a[i]);
    e=M<<1; 
    for(i=1;i<n;++i)
    {
        read(x);read(y);
        l[++e]=(edge){y,t[x]};t[x]=e;
        l[++e]=(edge){x,t[y]};t[y]=e;
    }
    e=1;
    for(i=1;i<=m;++i) 
    {
        read(x);read(y);
        l[++e]=(edge){y,qt[x]};qt[x]=e;
        l[++e]=(edge){x,qt[y]};qt[y]=e;
        if(x==y) {have[i]=1;ans[i]=a[x];}
    }
    for(i=1;i<=n;++i) 
    while(!vis[i]) solve(kcz::get_g(i));
    for(i=1;i<=m;++i) write(ans[i]);
    fwrite(ch,1,now_w-ch+1,stdout);
}