#include <bits/stdc++.h>
using namespace std;
typedef long long i64; 

int n, m; 
int f[15][20005], dep[20005];
i64 a[20005]; 

struct lb {
    i64 p[65];
    lb() { memset(p, 0, sizeof p); }
    void operator+= (i64 x) {
        for (int i = 61; i >= 0; --i) if (x >> i & 1) {
            if (!p[i]) { p[i] = x; break; }
            else x ^= p[i]; 
        }
    }
    i64 &operator[](int x) { return p[x]; }
    void operator+= (lb &x) {
        for (int i = 61; i >= 0; --i)
            if (x[i]) *this += x[i]; 
    }
    friend lb operator+(lb &x, lb &y) {
        lb z = x; 
        for (int i = 61; i >= 0; --i) if (y[i]) z += y[i]; 
        return z; 
    }
    i64 askmx(void) {
        i64 res = 0;
        for (int i = 61; i >= 0; --i) if ((res ^ p[i]) > res) res ^= p[i]; 
        return res;
    }
} l[15][20005]; 

vector<int> G[20005]; 
void dfs(int x, int fa) {
    l[0][x] += a[x]; dep[x] = dep[f[0][x] = fa] + 1; 
    for (int y : G[x]) if (y != fa) dfs(y, x); 
}

inline i64 query(int x, int y) {
    lb ans; 
    if (dep[x] < dep[y]) swap(x, y); 
    for (int i = 14; i >= 0; --i) if (dep[f[i][x]] >= dep[y]) 
        ans += l[i][x], x = f[i][x]; 
    if (x == y) return ans += a[x], ans.askmx(); 
    for (int i = 14; i >= 0; --i) if (f[i][x] != f[i][y])
        ans += l[i][x], ans += l[i][y], x = f[i][x], y = f[i][y]; 
    ans += l[0][x]; ans += l[0][y]; x = f[0][x]; ans += a[x]; 
    return ans.askmx(); 
}

int main(void) {
    ios::sync_with_stdio(0); 
    cin >> n >> m; 
    for (int i = 1; i <= n; ++i) cin >> a[i]; 
    for (int i = 1; i < n; ++i) {
        int x, y; cin >> x >> y; 
        G[x].emplace_back(y); G[y].emplace_back(x); 
    }
    dfs(1, 0);
    for (int i = 1; i <= 14; ++i) for (int j = 1; j <= n; ++j)
        f[i][j] = f[i - 1][f[i - 1][j]], l[i][j] = l[i - 1][j] + l[i - 1][f[i - 1][j]]; 
    while (m--) {
        int x, y; cin >> x >> y; 
        cout << query(x, y) << "\n"; 
    }
    return 0;
}