#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b)	for (int i(a); i <= (b); ++i)

#define dec(i, a, b)	for (int i(a); i >= (b); --i)

#define ls		i << 1

#define	rs		i << 1 | 1

#define lson		i << 1, L, mid

#define rson		i << 1 | 1, mid + 1, R

typedef long long LL;

const int N = 2e4 + 10;

struct lb{

	LL d[70];

	int cnt;

	void clear(){

		memset(d, 0, sizeof d);

		cnt = 0;

	}

	bool ins(LL val){

		dec(i, 62, 0) if (val & (1LL << i)){

			if (!d[i]){ d[i] = val; break; }

			val ^= d[i];

		}

		return val > 0;

	}

	LL qmax(){

		LL ret = 0;

		dec(i, 62, 0) if ((ret ^ d[i]) > ret) ret ^= d[i];

		return ret;

	}

	LL qmin(){

		rep(i, 0, 62) if (d[i]) return d[i];

		return 0;

	}

};

lb t[N << 3];

int f[N], fp[N], son[N], deep[N], father[N], sz[N], top[N];

int q, tot, n;

LL a[N];

vector <int> v[N];

lb merge(const lb &n1, const lb &n2){

	lb ret = n1;

	dec(i, 60, 0) if (n2.d[i]) ret.ins(n2.d[i]);

	return ret;

}

void dfs1(int x, int fa, int dep){

	deep[x] = dep;

	father[x] = fa;

	son[x] = 0;

	sz[x] = 1;

	int ct = (int)v[x].size();

	rep(i, 0, ct - 1){

		int u = v[x][i];

		if (u == fa) continue;

		dfs1(u, x, dep + 1);

		sz[x] += sz[u];

		if (sz[son[x]] < sz[u]) son[x] = u;

	}

}

void dfs2(int x, int tp){

	top[x] = tp;

	f[x] = ++tot;

	fp[f[x]] = x;

	if (son[x]) dfs2(son[x], tp);

	int ct = (int)v[x].size();

	rep(i, 0, ct - 1){

		int u = v[x][i];

		if (u == father[x] || u == son[x]) continue;

		dfs2(u, u);

	}

}

void build(int i, int L, int R){

	if (L == R){

		t[i].ins(a[fp[L]]);

		return;

	}

	int mid = (L + R) >> 1;

	build(lson);

	build(rson);

	t[i] = merge(t[ls], t[rs]);

}

lb query(int i, int L, int R, int l, int r){

	if (L == l && R == r) return t[i];

	int mid = (L + R) >> 1;

	if (r <= mid) return query(lson, l, r);

	else if (l > mid) return query(rson, l, r);

	else return merge(query(lson, l, mid), query(rson, mid + 1, r));

}

lb work(int x, int y){

	lb ret;

	ret.clear();

	int f1 = top[x], f2 = top[y];

	for (; f1 != f2; ){

		if (deep[f1] < deep[f2]) swap(f1, f2), swap(x, y);

		ret = merge(ret, query(1, 1, n, f[f1], f[x]));

		x = father[f1], f1 = top[x];

	}

	if (x == y) return merge(ret, query(1, 1, n, f[x], f[y]));

	if (deep[x] > deep[y]) swap(x, y);

	return merge(ret, query(1, 1, n, f[x], f[y]));

}

int main(){

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

	rep(i, 1, n) scanf("%lld", a + i);

	rep(i, 2, n){

		int x, y;

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

		v[x].push_back(y);

		v[y].push_back(x);

	}

	dfs1(1, 0, 0);

	dfs2(1, 1);

	build(1, 1, n);

	while (q--){

		int x, y;

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

		lb cnt = work(x, y);

		printf("%lld\n", cnt.qmax());

	}

	return 0;

}