#include <algorithm>
#include <iostream>
#include <fstream>
#include <climits>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <map>
#include <set>

#include <iomanip>
#include <cassert>

#include <random>
#include <chrono>

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

using ull = unsigned long long;
//using ll = long long;

//#define int __int128
//#define int ll
#define pii pair <int, int>
#define all(a) (a).begin(), (a).end()
#define fr first
#define sc second
#define pb push_back
#define lb lower_bound
#define ub upper_bound

#define vt vector
#define FOR(a, b) for(int i = (a); i <= (b); i++)
#define FORr(a, b) for(int i = (a); i >= (b); i--)
#define sz(x) (int)(x).size()

#define YES cout << "YES\n"
#define NO cout << "NO\n"

using namespace std;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int rangerng(int l, int r){
    return uniform_int_distribution<>(l, r)(rng);
}

string filename = "heavypath";
ifstream fin(filename + ".in");
ofstream fout(filename + ".out");

////////////////////////////////////////////////////////////////////////////////////

const int NMAX = 1e5;

int n;
int v[NMAX + 1];
vt <int> adj[NMAX + 1];

int lvl[NMAX + 1];
int h[NMAX + 1];
int p[NMAX + 1];
int sub[NMAX + 1];

void explore(int node, int par){
    p[node] = par;
    lvl[node] = lvl[par] + 1;
    sub[node] = 1;

    for(int vec : adj[node]){
        if(vec != par){
            explore(vec, node);
            sub[node] += sub[vec];
            if(sub[vec] > sub[h[node]]){
                h[node] = vec;
            }
        }
    }
}

int Id = 0;
int id[NMAX + 1];
int head[NMAX + 1];

int Tm = 0;
int lin[NMAX + 1];
int pos[NMAX + 1];

void heavy_first(int node, int par){
    lin[++Tm] = node;
    pos[node] = Tm;

    if(h[par] == node){
        id[node] = id[par];
    }else{
        ++Id;
        id[node] = Id;
        head[Id] = node;
    }

    if(h[node] != 0){
        heavy_first(h[node], node);
    }

    for(int vec : adj[node]){
        if(vec != par && vec != h[node]){
            heavy_first(vec, node);
        }
    }
}

namespace AINT{
    int aint[4 * NMAX + 1];

    void build(int node, int l, int r){
        if(l == r){
            aint[node] = v[lin[l]];
            return;
        }

        int mid = (l + r) / 2;
        build(2 * node, l, mid);
        build(2 * node + 1, mid + 1, r);
        aint[node] = max(aint[2 * node], aint[2 * node + 1]);
    }

    void update(int node, int l, int r, int pos, int val){
        if(l == r){
            aint[node] = val;
            return;
        }

        int mid = (l + r) / 2;
        if(pos <= mid){
            update(2 * node, l, mid, pos, val);
        }else{
            update(2 * node + 1, mid + 1, r, pos, val);
        }

        aint[node] = max(aint[2 * node], aint[2 * node + 1]);
    }

    int query(int node, int l, int r, int ql, int qr){
        if(ql <= l && r <= qr){
            return aint[node];
        }

        int ans = 0, mid = (l + r) / 2;
        if(ql <= mid){
            ans = max(ans, query(2 * node, l, mid, ql, qr));
        }
        if(mid + 1 <= qr){
            ans = max(ans, query(2 * node + 1, mid + 1, r, ql, qr));
        }

        return ans;
    }
}

int query(int x, int y){
    int ans = 0;
    while(id[x] != id[y]){
        //cout << x << ' ' << y << endl;
        if(lvl[x] > lvl[y]){
            ans = max(ans, AINT::query(1, 1, n, pos[head[id[x]]], pos[x]));
            x = p[head[id[x]]];
        }else{
            ans = max(ans, AINT::query(1, 1, n, pos[head[id[y]]], pos[y]));
            y = p[head[id[y]]];
        }
    }
    //cout << "!!1\n";
    if(x != 0){
        ans = max(ans, AINT::query(1, 1, n, min(pos[x], pos[y]), max(pos[x], pos[y])));
    }
    //cout << "!!2\n";
    return ans;
}

void solve(){
    int q;
    fin >> n >> q;

    for(int i = 1; i <= n; i++){
        fin >> v[i];
    }

    for(int i = 1; i <= n - 1; i++){
        int a, b;
        fin >> a >> b;
        adj[a].pb(b);
        adj[b].pb(a);
    }

    explore(1, 0);
    heavy_first(1, 0);

    AINT::build(1, 1, n);


    while(q--){
        int type;
        fin >> type;

        if(type == 0){
            int node, x;
            fin >> node >> x;
            AINT::update(1, 1, n, pos[node], x);
        }else{
            int x, y;
            fin >> x >> y;
            fout << query(x, y) << '\n';
        }
    }
}   


signed main(){

    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int T;
    //fin >> T;

    T = 1;

    while(T--){
        solve();
    }

    return 0;
}

/*
*/