#include <bits/stdc++.h>
#define pb push_back

using namespace std;

ifstream fin("heavypath.in");
ofstream fout("heavypath.out");

void debug_out() { cerr << '\n'; }
template <typename Head, typename... Tail> void debug_out(Head H, Tail... T) { cerr << " " << H; debug_out(T...);}
#define dbg(...) cerr << #__VA_ARGS__ << " ->", debug_out(__VA_ARGS__)
#define dbg_v(x, n) do{cerr<<#x"[]: ";for(int _=0;_<n;++_)cerr<<x[_]<<" ";cerr<<'\n';}while(0)
#define dbg_ok cerr<<"OK!\n"

typedef pair<int,int> pii;
typedef long long int ll;
typedef long double ld;

const int DMAX = 1e5+10;

vector <int> vec;
vector <int> arb[DMAX];
vector <vector<int>> lant;
vector <vector<int>> tree;

int V[DMAX];
int nivel[DMAX];
int tatal[DMAX];
int lnt[DMAX];
int pos[DMAX];
int dp[DMAX];

int n,q,fr;

void dfs(int node,int tata);
void dfs2(int node,int tata);
void build(int node,int st,int dr,int id);
void update(int node,int st,int dr,int pos,int val,int id);
int query(int node,int st,int dr,int x,int y,int id);

int main(){
    int t,i,j;
    int x,y;

    fin>>n>>q;
    for(i=1;i<=n;i++)
        fin>>V[i];
    for(i=1;i<n;i++){
        fin>>x>>y;
        arb[x].pb(y);
        arb[y].pb(x);
    }
    dfs(1,0);
    lant.resize(fr+1);
    tree.resize(fr+1);
    fr=0;
    dfs2(1,0);

    for(i=1;i<=fr;i++){
        tree[i].resize(4*lant[i].size()+5);
        build(1,1,lant[i].size(),i);
    }
    bool op;
    while(q--){
        fin>>op>>x>>y;
        if(!op){
            update(1,1,lant[lnt[x]].size(),pos[x],y,lnt[x]);
            continue;
        }
        int ans=0;
        while(lnt[x] != lnt[y]){
            if(nivel[lant[lnt[x]].back()] > nivel[lant[lnt[y]].back()]){
                ans=max(ans,query(1,1,lant[lnt[x]].size(),pos[x],lant[lnt[x]].size(),lnt[x]));
                x=tatal[lant[lnt[x]].back()];
            }
            else{
                ans=max(ans,query(1,1,lant[lnt[y]].size(),pos[y],lant[lnt[y]].size(),lnt[y]));
                y=tatal[lant[lnt[y]].back()];
            }
        }
        if(nivel[x] < nivel[y])
            swap(x,y);
        ans=max(ans,query(1,1,lant[lnt[x]].size(),pos[x],pos[y],lnt[x]));
        fout<<ans<<'\n';
    }

    return 0;
}
void dfs(int node,int tata){
    nivel[node]=nivel[tata]+1;
    tatal[node]=tata;
    dp[node]=1;
    for(auto& it:arb[node])
        if(it != tata){
            dfs(it,node);
            dp[node]+=dp[it];
        }
    if(dp[node] == 1)
        fr++;
}
void dfs2(int node,int tata){
    for(auto& it:arb[node])
        if(it != tata)
            dfs2(it,node);
    if(dp[node] == 1){
        lnt[node]=++fr;
        lant[fr].pb(node);
        pos[node]=1;
        return;
    }
    int best=0,nodul;
    for(auto& it:arb[node])
        if(it != tata){
            if(best < dp[it]){
                best=dp[it];
                nodul=it;
            }
        }
    lnt[node]=lnt[nodul];
    lant[lnt[node]].pb(node);
    pos[node]=lant[lnt[node]].size();
}
void build(int node,int st,int dr,int id){
    if(st == dr){
        tree[id][node]=V[lant[id][st-1]];
        return;
    }
    int mij=(st+dr)/2;
    build(2*node,st,mij,id);
    build(2*node+1,mij+1,dr,id);
    tree[id][node]=max(tree[id][2*node],tree[id][2*node+1]);
}
void update(int node,int st,int dr,int pos,int val,int id){
    if(st == dr){
        tree[id][node]=val;
        return;
    }
    int mij=(st+dr)/2;
    if(pos <= mij)
        update(2*node,st,mij,pos,val,id);
    else
        update(2*node+1,mij+1,dr,pos,val,id);
    tree[id][node]=max(tree[id][2*node],tree[id][2*node+1]);
}
int query(int node,int st,int dr,int x,int y,int id){
    if(x <= st && dr <= y)
        return tree[id][node];
    int mij=(st+dr)/2;
    int ans=0;
    if(x <= mij)
        ans=query(2*node,st,mij,x,y,id);
    if(y > mij)
        ans=max(ans,query(2*node+1,mij+1,dr,x,y,id));
    return ans;
}