#include <bits/stdc++.h>
using namespace std;
ifstream fin("heavypath.in");
ofstream fout("heavypath.out");
const int N = 100000,logn = 17;
int v[N],sub[N],cnt = 0;
pair <int,int> hpdp[N];
int endpoint[N];
int dpth[N];
vector <int> v2[N];
vector<int> seg[N];
vector<int> e[N];
int parent[logn][N];
void dfs(int node,int p = -1,int d = 0){
    sub[node] = 1;
    dpth[node] = d;
    parent[0][node] = (p == -1?node:p);
    for(auto i:e[node]){
        if(i == p)continue;
        dfs(i,node,d + 1);
        sub[node]+=sub[i];
    }
    bool ok = 0;
    for(auto i:e[node]){
        if(i == p)continue;
        if(sub[node]/2 <= sub[i]){
            ///heavy
            ok = 1;
            hpdp[node] = {hpdp[i].first,v2[hpdp[i].first].size()};
            v2[hpdp[i].first].push_back(v[node]);
            break;
        }
    }
    if(!ok){
        ///new component
        hpdp[node] = {cnt++,0};
        v2[cnt - 1].push_back(v[node]);
    }
}
void dfs2(int node,int p = -1){
    if(p != -1 && hpdp[p].first == hpdp[node].first){
        endpoint[node] = endpoint[p];
    }else{
        endpoint[node] = node;
    }
    for(auto i:e[node]){
        if(i == p)continue;
        dfs2(i,node);
    }
}
int lca(int a,int b){
    if(dpth[a] < dpth[b]){
        swap(a,b);
    }
    for(int i = logn - 1;i >= 0;i--){
        if(dpth[a] - (1<<i) >= dpth[b]){
            a = parent[i][a];
        }
    }
    for(int i = logn - 1;i >= 0;i--){
        if(parent[i][a] != parent[i][b]){
            a = parent[i][a];
            b = parent[i][b];
        }
    }
    if(a != b){
        return parent[0][a];
    }else return a;
}
void build(int id,int l,int r,int node = 1){
    if(l == r){
        seg[id][node] = v2[id][l];
    }else{
        int mij = (l + r)/2;
        build(id,l,mij,node*2);
        build(id,mij + 1,r,node*2 + 1);
        seg[id][node] = max(seg[id][node*2],seg[id][node*2 + 1]);
    }
}
void modify(int id,int target,int nr,int l,int r,int node = 1){
    if(l == r){
        v2[id][target] = nr;
        seg[id][node] = nr;
    }else{
        int mij = (l + r)/2;
        if(target <= mij){
            modify(id,target,nr,l,mij,node*2);
        }else{
            modify(id,target,nr,mij + 1,r,node*2 + 1);
        }
        seg[id][node] = max(seg[id][node*2],seg[id][node*2 + 1]);
    }
}
int query(int id,int l2,int r2,int l,int r,int node = 1){
    if(l2 > r2)swap(l2,r2);
    int nr = 0;
    if(l2 <= l && r <= r2){
        nr = seg[id][node];
    }else{
        int mij = (l + r)/2;
        if(l2 <= mij)nr = max(nr,query(id,l2,r2,l,mij,node*2));
        if(mij + 1 <= r2)nr = max(nr,query(id,l2,r2,mij + 1,r,node*2 + 1));
    }
    return nr;
}
int query2(int node,int p){
    int ans = 0;
    if(hpdp[node].first != hpdp[p].first){
        ///node -> endpoint
        ans = query(hpdp[node].first,hpdp[node].second,hpdp[endpoint[node]].second,0,v2[hpdp[node].first].size() - 1);
        ans = max(ans,query2(parent[0][endpoint[node]],p));
    }else{
        ///node -> c
        ans = query(hpdp[node].first,hpdp[node].second,hpdp[p].second,0,v2[hpdp[node].first].size() - 1);
    }
    return ans;
}
int main(){
    int n,q,i,j,u,w,cer,a,b;
    fin>>n>>q;
    for(i = 0;i < n;i++){
        fin>>v[i];
    }
    for(i = 0;i < n - 1;i++){
        fin>>u>>w;
        u--;w--;
        e[u].push_back(w);
        e[w].push_back(u);
    }
    dfs(0);
    dfs2(0);
    for(i = 1;i < logn;i++){
        for(j = 0;j < n;j++){
            parent[i][j] = parent[i - 1][parent[i - 1][j]];
        }
    }
    for(i = 0;i < n;i++){
        if(v2[i].size() == 0)continue;
        seg[i].resize(v2[i].size()*4);
        ///build segment tree
        build(i,0,v2[i].size() - 1);
    }
    for(i = 0;i < q;i++){
        fin>>cer>>a>>b;
        a--;b--;
        if(cer == 1){
            int c = lca(a,b);
            fout<<max(query2(a,c),query2(b,c))<<'\n';;
        }else{
            b++;
            v[a] = b;
            v2[hpdp[a].first][hpdp[a].second] = b;
            modify(hpdp[a].first,hpdp[a].second,b,0,v2[hpdp[a].first].size() - 1);
        }
    }
    return 0;
}