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