#include <fstream>
#include <vector>
std::ifstream cin("heavypath.in");
std::ofstream cout("heavypath.out");
const int MAXN = 1e5 + 1;
class SegmenTree {
protected:
std::vector<int> tree;
int root, Left, Right;
public:
void init(const int& size) {
tree.resize(2 * size);
root = 1;
Left = 0;
Right = size - 1;
}
void update(const int& poz, const int& val) {
updatePoz(root, Left, Right, poz, val);
}
int query(const int& l, const int& r) {
return queryIntv(root, Left, Right, l, r);
}
private:
void updatePoz(int node, int left, int right, const int& poz, const int& val) {
if(left == right) {
tree[node] = val;
} else {
int mid = (left + right) >> 1;
int L = node + 1;
int R = node + 2 * (mid - left + 1);
if(poz <= mid)
updatePoz(L, left, mid, poz, val);
else updatePoz(R, mid + 1, right, poz, val);
tree[node] = std::max(tree[L], tree[R]);
}
}
int queryIntv( int nod, int l, int r, int lq, int rq ) {
if( r < lq || l > rq )
return 0;
if( lq <= l && r <= rq )
return tree[ nod ];
int med = ( l + r ) >> 1;
int R = nod + 2 * ( med - l + 1 );
int L = nod + 1;
return std::max( queryIntv( L, l, med, lq, rq ), queryIntv( R, med + 1, r, lq, rq ) );
}
};
class HeavyMax {
protected:
int poz;
SegmenTree maxTree;
std::vector<int> pos, head;
std::vector<int> heavy, depth;
std::vector<int> parent, edges[MAXN];
public:
void init(const int& size) {
maxTree.init(size);
pos.resize(size + 1);
head.resize(size);
heavy.resize(size);
depth.resize(size);
parent.resize(size);
poz = 0;
depth[0] = 0;
dfs(0, -1);
decompose(0, -1, 0);
}
void addEdge(const int& u, const int& v) {
edges[u].push_back(v);
edges[v].push_back(u);
}
void update(int u, int val) {
maxTree.update(pos[u], val);
}
int query(const int& u, const int& v) {
return queryHeavy(u, v);
}
private:
int dfs(int u, const int& p) {
int sizeV;
int sizeU = 1;
int maxSize = 0;
heavy[u] = -1;
parent[u] = p;
for(const int& v : edges[u])
if(v != p) {
depth[v] = depth[u] + 1;
sizeV = dfs(v, u);
sizeU += sizeV;
if(sizeV > maxSize) {
maxSize = sizeV;
heavy[u] = v;
}
}
return sizeU;
}
void decompose(int u, const int& p, int h) {
head[u] = h;
pos[u] = poz++;
if(heavy[u] != -1)
decompose(heavy[u], u, h);
for(const int& v : edges[u])
if(v != p && v != heavy[u])
decompose(v, u, v);
}
int queryHeavy(int u, int v) {
int ans = -1e9;
while(head[u] != head[v]) {
if(depth[head[u]] > depth[head[v]])
std::swap(u, v);
ans = std::max(ans, maxTree.query(pos[head[v]], pos[v]));
v = parent[head[v]];
}
ans = std::max(ans, maxTree.query(std::min(pos[u], pos[v]), std::max(pos[u], pos[v])));
return ans;
}
};
HeavyMax maxy;
int val[MAXN];
int n, q;
void readAndSolveQueryAndPrint() {
int u, v;
int type;
while(q--) {
cin >> type;
cin >> u >> v;
if(type == 0)
maxy.update(u - 1, v);
else cout << maxy.query(u - 1, v - 1) << '\n';
}
}
void readEdgesAndInitHeavy() {
int u, v;
for(int i = 1; i < n; i++) {
cin >> u >> v;
maxy.addEdge(u - 1, v - 1);
}
maxy.init(n);
for( int u = 0; u < n; u++ )
maxy.update( u, val[ u ] );
}
void readBaseInput() {
cin >> n >> q;
for(int i = 0; i < n; i++)
cin >> val[i];
}
int main()
{
readBaseInput();
readEdgesAndInitHeavy();
readAndSolveQueryAndPrint();
return 0;
}