#include <bits/stdc++.h>
using namespace std;
ifstream fin ("heavypath.in");
ofstream fout ("heavypath.out");
void usain_bolt()
{
ios::sync_with_stdio(false);
fin.tie(0);
}
const int N = 1e5 + 5;
vector < int > a[N];
vector < int > lant[N];
int val[N], sz[N], h[N], heavy[N], dad[N], pos[N], place[N], total, tree[N * 4], delay[N];
bool f[N];
void update(int left, int right, int node, int pos, int val, int dist)
{
if(left > right) return ;
if(left == right) {
tree[node + dist] = val;
return ;
}
int mid = (left + right) >> 1;
if(pos <= mid) {
update(left, mid, node * 2, pos, val, dist);
}
else {
update(mid + 1, right, node * 2 + 1, pos, val, dist);
}
tree[node + dist] = max(tree[node * 2 + dist], tree[node * 2 + 1 + dist]);
}
int query(int left, int right, int node, int x, int y, int dist)
{
if(left > right) return 0;
if(left >= x && right <= y) {
return tree[node + dist];
}
int mid = (left + right) >> 1;
int ans1 = 0, ans2 = 0;
if(mid >= x) {
ans1 = query(left, mid, node * 2, x, y, dist);
}
if(mid + 1 <= y) {
ans2 = query(mid + 1, right, node * 2 + 1, x, y, dist);
}
return max(ans1, ans2);
}
void build()
{
int sum = 0;
for(int i = 1; i <= total; ++i) {
delay[i] = sum;
for(auto v : lant[i]) {
update(1, (int) lant[i].size(), 1, pos[v], val[v], delay[i]);
}
sum += (int) lant[i].size() * 4;
}
}
int dfs(int k, int daddy)
{
f[k] = true;
h[k] = h[daddy] + 1;
for(auto v : a[k]) {
if(f[v] == false) {
dad[v] = k;
dfs(v, k);
sz[k] += sz[v];
if(sz[v] > sz[heavy[k]] || heavy[k] == 0) {
heavy[k] = v;
}
}
}
}
int divide(int k, int act_lant)
{
f[k] = true;
lant[act_lant].push_back(k);
place[k] = act_lant;
pos[k] = (int) lant[act_lant].size();
if(heavy[k] != 0) {
divide(heavy[k], act_lant);
}
for(auto v : a[k]) {
if(f[v] == false) {
divide(v, ++total);
}
}
}
int solve(int x, int y)
{
int ans = 0;
while(place[x] != place[y]) {
if(h[lant[place[x]][0]] < h[lant[place[y]][0]]) {
swap(x, y);
}
ans = max(ans, query(1, (int) lant[place[x]].size(), 1, 1, pos[x], delay[place[x]]));
x = dad[lant[place[x]][0]];
}
if(pos[x] > pos[y]) {
swap(x, y);
}
ans = max(ans, query(1, (int) lant[place[x]].size(), 1, pos[x], pos[y], delay[place[x]]));
return ans;
}
int main()
{
usain_bolt();
int n, m;
fin >> n >> m;
for(int i = 1; i <= n; ++i) {
fin >> val[i];
}
for(int i = 1; i < n; ++i) {
int x, y;
fin >> x >> y;
a[x].push_back(y);
a[y].push_back(x);
}
dfs(1, 0);
memset(f, 0, sizeof(f));
divide(1, ++total);
build();
for(; m; --m) {
int type, x, y;
fin >> type >> x >> y;
if(type == 0) {
update(1, (int) lant[place[x]].size(), 1, pos[x], y, delay[place[x]]);
}
else {
fout << solve(x, y) << "\n";
}
}
return 0;
}