#include <bits/stdc++.h>

using namespace std;
class HeavyPath {
    int n, k;
    vector <vector <int>>& g;
    vector <int> t, trans, path, head, h, sz;
    vector <vector <int>> comp;
    void dfs(int u, int p) {
        h[u] = h[p] + 1;
        int link = 0;
        for(int v : g[u]) if(v != p) {
            dfs(v, u);
            sz[u] += sz[v];
            if(sz[v] > sz[link])
                link = v;
        }
        if(link == 0) path[u] = k++;
        else path[u] = path[link];
        comp[path[u]].push_back(u);
        for(int v : g[u]) if(v != p && v != link)
            head[path[v]] = u;
    }
    void light_update(int pos, int x) {
        for(t[pos += n] = x; pos > 1; pos >>= 1)
            t[pos >> 1] = max(t[pos], t[pos ^ 1]);
    }
    int heavy_query(int l, int r) {
        int res = 0;
        for(l += n, r += n; l < r; l >>= 1, r >>= 1) {
            if(l & 1) res = max(res, t[l++]);
            if(r & 1) res = max(res, t[--r]);
        }
        return res;
    }
public:
    HeavyPath(int n, int* val, vector <vector <int>>& _g) : n(n), k(0), g(_g), t(2 * n), trans(n + 1, 0), path(n + 1, 0), head(n + 1, 0), h(n + 1, 0), sz(n + 1, 1), comp(n + 1) {
        sz[0] = 0; dfs(1, 0);
        for(int i = 0, cnt = 0; i < k; i++)
            for(int u : comp[i])
                trans[u] = cnt++;
        for(int i = 1; i <= n; i++)
            t[trans[i] + n] = val[i];
        for(int i = n - 1; i > 0; i--)
            t[i] = max(t[i << 1], t[i << 1 | 1]);
    }
    void update(int x, int y) { return light_update(trans[x], y); }
    int query(int x, int y) {
        int res = 0;
        for(; path[x] != path[y]; x = head[path[x]]) {
            if(h[head[path[x]]] < h[head[path[y]]]) swap(x, y);
            res = max(res, heavy_query(trans[x], trans[comp[path[x]].back()] + 1));
        }
        if(trans[x] > trans[y]) swap(x, y);
        return max(res, heavy_query(trans[x], trans[y] + 1));
    }
};
const int N = 1e5;
int val[N + 5];
vector <vector <int>> g;

int main()
{
    ifstream cin("heavypath.in");
    ofstream cout("heavypath.out");
    int n, m, u, v;
    cin >> n >> m;
    g.resize(n + 1);
    for(int i = 1; i <= n; i++)
        cin >> val[i];
    for(int i = 1; i < n; i++)
        cin >> u >> v,
        g[u].push_back(v),
        g[v].push_back(u);
    HeavyPath HLD(n, val, g);
    for(int i = 1; i <= m; i++) {
        int t, x, y;
        cin >> t >> x >> y;
        if(t == 1) cout << HLD.query(x, y) << "\n";
        else HLD.update(x, y);
    }
    return 0;
}