#include <fstream>
#include <iostream>
#include <vector>
#include <bitset>
#include <string.h>
#include <algorithm>
#include <iomanip>
#include <math.h>
#include <time.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <deque>
using namespace std;
const char infile[] = "heavypath.in";
const char outfile[] = "heavypath.out";
ofstream fout(outfile);
const int MAXN = 100005;
const int oo = 0x3f3f3f3f;
typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;
const inline int min(const int &a, const int &b) { if( a > b ) return b; return a; }
const inline int max(const int &a, const int &b) { if( a < b ) return b; return a; }
const inline void Get_min(int &a, const int b) { if( a > b ) a = b; }
const inline void Get_max(int &a, const int b) { if( a < b ) a = b; }
const int lim = (1 << 20);
char buff[lim];
int pos;
inline void get(int &x) {
x = 0;
while(!('0' <= buff[pos] && buff[pos] <= '9'))
if(++ pos == lim) {
fread(buff, 1, lim, stdin);
pos = 0;
}
while('0' <= buff[pos] && buff[pos] <= '9') {
x = x * 10 + buff[pos] - '0';
if(++ pos == lim) {
fread(buff, 1, lim, stdin);
pos = 0;
}
}
}
int N, M, v[MAXN];
int numPaths, pathWhere[MAXN], pathFather[MAXN], pathPosition[MAXN];
int depth[MAXN], heavy[MAXN];
Graph G, arb, Path;
inline void DFs(int Node, int Father, int actLevel) {
heavy[Node] = 1;
depth[Node] = actLevel;
int heaviest = -1;
for(It it = G[Node].begin(), fin = G[Node].end(); it != fin ; ++ it) {
if(*it == Father)
continue;
DFs(*it, Node, actLevel + 1);
heavy[Node] += heavy[*it];
if(heaviest == -1 || heavy[*it] > heavy[heaviest])
heaviest = *it;
}
if(heaviest == -1) {
pathWhere[Node] = ++ numPaths;
Path[pathWhere[Node]].push_back(Node);
pathFather[pathWhere[Node]] = Father;
return;
}
pathWhere[Node] = pathWhere[heaviest];
Path[pathWhere[Node]].push_back(Node);
pathFather[pathWhere[Node]] = Father;
}
inline void Build(int Node, int st, int dr, int where) {
if(st == dr) {
arb[where][Node] = v[Path[where][st]];
return;
}
int mid = ((st + dr) >> 1);
Build(Node << 1, st, mid, where);
Build((Node << 1) | 1, mid+1, dr, where);
arb[where][Node] = max(arb[where][Node << 1], arb[where][(Node << 1) | 1]);
}
inline void Update(int Node, int st, int dr, int pos, int where) {
if(st == dr) {
arb[where][Node] = v[Path[where][st]];
return;
}
int mid = ((st + dr) >> 1);
if(pos <= mid)
Update(Node << 1, st, mid, pos, where);
else
Update((Node << 1) | 1, mid+1, dr, pos, where);
arb[where][Node] = max(arb[where][Node << 1], arb[where][(Node << 1) | 1]);
}
inline int Query(int Node, int st, int dr, int a, int b, int where) {
if(a <= st && dr <= b)
return arb[where][Node];
int mid = ((st + dr) >> 1);
int ans = -oo;
if(a <= mid)
ans = max(ans, Query(Node << 1, st, mid, a, b, where));
if(mid < b)
ans = max(ans, Query((Node << 1) | 1, mid+1, dr, a, b, where));
return ans;
}
inline int QueryHeavyPath(int x, int y) {
if(pathWhere[x] == pathWhere[y]) {
if(pathPosition[x] > pathPosition[y])
swap(x, y);
return Query(1, 0, Path[pathWhere[x]].size() - 1, pathPosition[x], pathPosition[y], pathWhere[x]);
}
if(depth[pathFather[pathWhere[x]]] < depth[pathFather[pathWhere[y]]])
swap(x, y);
int act = Query(1, 0, Path[pathWhere[x]].size() - 1, 0, pathPosition[x], pathWhere[x]);
return max(act, QueryHeavyPath(pathFather[pathWhere[x]], y));
}
int main() {
freopen(infile, "r", stdin);
get(N); get(M);
for(int i = 1 ; i <= N ; ++ i)
get(v[i]);
for(int i = 1 ; i < N ; ++ i) {
int x, y;
get(x);
get(y);
G[x].push_back(y);
G[y].push_back(x);
}
DFs(1, 0, 1);
for(int i = 1 ; i <= numPaths ; ++ i) {
reverse(Path[i].begin(), Path[i].end());
for(int j = 0 ; j < int(Path[i].size()) ; ++ j)
pathPosition[Path[i][j]] = j;
arb[i].resize(4*Path[i].size());
Build(1, 0, Path[i].size() - 1, i);
}
for(int i = 1 ; i <= M ; ++ i) {
int op, x, y;
get(op);
get(x);
get(y);
switch(op) {
case 0:
v[x] = y;
Update(1, 0, Path[pathWhere[x]].size() - 1, pathPosition[x], pathWhere[x]);
break;
case 1:
fout << QueryHeavyPath(x, y) << '\n';
break;
}
}
fout.close();
return 0;
}