///heavy[nod] -> fiul care are subarborele maximal
#include <fstream>
#include <vector>
#include <string.h>
using namespace std;
ifstream cin ("heavypath.in");
ofstream cout ("heavypath.out");
const int N = 1e5;
int a[N + 1], heavy[N + 1], dep[N + 1], tata[N + 1], siz[N + 1], id_node[N + 1], head[N + 1], poz[N + 1], poz_in_aint[N + 1];
vector <int> g[N + 1];
int n, m, x, y, cer, timp, nr_lant;
void dfs (int node, int parent)
{
dep[node] = dep[parent] + 1;
tata[node] = parent;
siz[node] = 1;
for (auto it : g[node])
if (it != parent)
{
dfs (it, node);
siz[node] += siz[it];
if (siz[heavy[node]] < siz[it])
heavy[node] = it;
}
}
void heavy_first (int node, int parent)
{
++timp;
poz[node] = timp;
poz_in_aint[timp] = node;
if (heavy[parent] == node)
id_node[node] = id_node[parent];
else
{
++nr_lant;
id_node[node] = nr_lant;
head[nr_lant] = node;
}
if (heavy[node])heavy_first (heavy[node], node);
for (auto it : g[node])
if (it != parent && it != heavy[node])
heavy_first (it, node);
}
struct segtree
{
int v[N * 3 + 1];
segtree ()
{
memset (v, 0, sizeof(v));
}
int combine (int a, int b)
{
return max (a, b);
}
void build (int node, int l, int r)
{
if (l == r)
{
v[node] = a[poz_in_aint[l]];
return;
}
int mid = (l + r) >> 1;
build (node << 1, l, mid);
build (node << 1 | 1, mid + 1, r);
v[node] = combine (v[node << 1], v[node << 1 | 1]);
}
void update (int node, int l, int r, int pos, int val)
{
if (l == r)
{
v[node] = val;
return;
}
int mid = (l + r) >> 1;
if (pos <= mid)update (node << 1, l, mid, pos, val);
else update (node << 1 | 1, mid + 1, r, pos, val);
v[node] = combine (v[node << 1], v[node << 1 | 1]);
}
int query (int node, int l, int r, int st, int dr)
{
if (l >= st && r <= dr)
return v[node];
int mid = (l + r) >> 1;
int a, b;
a = b = 0;
if (st <= mid)a = query (node << 1, l, mid, st, dr);
if (dr > mid)b = query (node << 1 | 1, mid + 1, r, st, dr);
return combine (a, b);
}
} arb;
int query (int x, int y)
{
int ans = 0;
while (id_node[x] != id_node[y])
{
int capx = head[id_node[x]];
int capy = head[id_node[y]];
if (dep[capx] < dep[capy])
{
int pos_cap = poz[capy];
ans = max (ans, arb.query (1, 1, n, pos_cap, poz[y]));
y = tata[capy];
}
else
{
int pos_cap = poz[capx];
ans = max (ans, arb.query (1, 1, n, pos_cap, poz[x]));
x = tata[capx];
}
}
int posx = poz[x];
int posy = poz[y];
ans = max (ans, arb.query (1, 1, n, min (posx, posy), max (posx, posy)));
return ans;
}
int main()
{
cin >> n >> m;
for (int i = 1; i <= n; ++i)
cin >> a[i];
for (int i = 1; i < n && cin >> x >> y; ++i)g[x].push_back(y), g[y].push_back(x);
dfs (1, 0);
heavy_first (1, 0);
arb.build (1, 1, n);
for (int i = 1; i <= m && cin >> cer >> x >> y; ++i)
{
if (!cer)
arb.update (1, 1, n, poz[x], y);
else
cout << query (x, y) << '\n';
}
return 0;
}