#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
std::ifstream in("heavypath.in");
std::ofstream out("heavypath.out");
const int INF = 2e9;
const int NMAX = 1e5;
using namespace std;
vector<int>g[NMAX + 1], heavyhead, sz, HFindex, parent, st, en, heavychild, depth, cost;
int n, m, task, u, v, val, timer, index, ans;
vector<int>aint;

void set_fast() {
	ios_base::sync_with_stdio(false);
	in.tie(nullptr);
	out.tie(nullptr);
}

void dfs(int node = 1, int p = 0) {
	sz[node] = 1;
	st[node] = ++timer;
	for (auto i : g[node]) {
		if (i ^ p) {
			depth[i] = depth[node] + 1;
			parent[i] = node;
			dfs(i, node);
			sz[node] += sz[i];
			if (sz[heavychild[node]] < sz[i])
				heavychild[node] = i;
		}
	}
	en[node] = timer;
}

void heavy_first(int node = 1) {
	HFindex[node] = ++index;
	if (heavychild[node]) {
		heavyhead[heavychild[node]] = heavyhead[node];
		heavy_first(heavychild[node]);
	}
	for (auto i : g[node])
		if (sz[i] < sz[node] && i ^ heavychild[node]) {
			heavyhead[i] = i;
			heavy_first(i);
		}
}

void query_max(int st, int dr, int node = 1, int l = 1, int r = n) {
	if (st <= l && r <= dr) {
		ans = max(ans, aint[node]);
		return;
	}
	int mid = (l + r) >> 1;
	if (st <= mid) query_max(st, dr, node * 2, l, mid);
	if (mid < dr) query_max(st, dr, node * 2 + 1, mid + 1, r);
}

void update(int pos, int val, int node = 1, int l = 1, int r = n) {
	if (l == r) {
		aint[node] = val;
		return;
	}
	int mid = (l + r) >> 1;
	if (pos <= mid) update(pos, val, node * 2, l, mid);
	else update(pos, val, node * 2 + 1, mid + 1, r);
	aint[node] = max(aint[node * 2], aint[node * 2 + 1]);
}

int solve_query(int st, int dr) {
	ans = -INF;
	query_max(st, dr);
	return ans;
}

int queryOnPath(int u, int v) {
	if (heavyhead[u] == heavyhead[v]) {
		if (depth[heavyhead[u]] < depth[heavyhead[v]])
			return solve_query(HFindex[u], HFindex[v]);
		else return solve_query(HFindex[v], HFindex[u]);
	}
	else {
		if (depth[heavyhead[u]] > depth[heavyhead[v]])
			return max(solve_query(HFindex[heavyhead[u]], HFindex[u]), queryOnPath(parent[heavyhead[u]], v));
		else return max(solve_query(HFindex[heavyhead[v]], HFindex[v]), queryOnPath(u, parent[heavyhead[v]]));
	}
}

int main() {
	set_fast();
	in >> n >> m;
	heavyhead = sz = HFindex = parent = st = en = heavychild = depth = cost = vector<int>(n + 1);
	aint = vector<int>(4 * n + 1);

	for (int i = 1; i <= n; i++) in >> cost[i];
	for (int i = 1; i < n; i++) {
		in >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}

	heavyhead[1] = 1;
	dfs();
	heavy_first();

	for (int i = 1; i <= n; i++) update(HFindex[i], cost[i]);

	while (m--) {
		in >> task >> u >> v;
		if (!task) update(HFindex[u], v);
		else out << queryOnPath(u, v) << '\n';
	}
	return 0;
}