#include <iostream>
#include <vector>
#include <algorithm>
#include <limits>
#include <numeric>
#include <cstring>
#include <string>
#include <queue>
#include <set>
#include <cmath>
#include <fstream>
#include <cstdlib>
#include <map>
#include <stack>
#define pb push_back
#define mp make_pair
#define INF numeric_limits<int>::max()
#define lsb(x) (-x)&x
#define int64 long long
using namespace std;
ifstream in("heavypath.in");
ofstream out("heavypath.out");
vector< vector<int> > adj;
vector<int> v,firstNode,comp,parent,pathPos,tree;
priority_queue< pair<int,int> > leafs;
int n,k,np;
vector<int> T2,lvl;
void dfs(int x,int px,int n1,int niv)
{
    lvl[x]=niv;
    T2[x]=n1;
    parent[x]=px;
    if(niv%200==0)
        n1=x;
    if(adj[x].size()==1 && x!=1)
        leafs.push(mp(lvl[x],x));
    else for(auto it: adj[x])
        if(it!=px)
        dfs(it,x,n1,niv+1);
}
int LCA(int xx, int yy)
{
    int x=xx,y=yy;
    while(T2[x] != T2[y])
        if(lvl[x] > lvl[y])
            x = T2[x];
        else
            y = T2[y];

    while(x != y)
        if(lvl[x] > lvl[y])
            x = parent[x];
        else
            y = parent[y];

    return x;
}

void pathUpd(int x,int left,int right,int position,int val)
{
    if(left==right)
        tree[x]=val;
    else{
        int mid=(left+right)/2;
        if(position<=mid)
            pathUpd(2*x,left,mid,position,val);
        else
            pathUpd(2*x+1,mid+1,right,position,val);
        tree[x]=max(tree[2*x],tree[2*x+1]);
    }
}
int sol;
void pathQuery(int x,int left,int right,int a,int b)
{
    if(a<=left && b>=right)
        sol=max(sol,tree[x]);
    else{
        int mid=(left+right)/2;
        if(a<=mid)
            pathQuery(2*x,left,mid,a,b);
        if(b>mid)
            pathQuery(2*x+1,mid+1,right,a,b);
    }
}
void update(int x,int val)
{
    pathUpd(1,1,n,pathPos[x],val);
}
void getMax(int x,int lca)
{
    int node=x;
    while(comp[node]!=comp[lca])
    {
        pathQuery(1,1,n,pathPos[ firstNode[ comp[node] ] ],pathPos[node]);
        node=parent[ firstNode[ comp[node] ] ];
    }
    pathQuery(1,1,n,pathPos[lca],pathPos[node]);
}
int query(int x,int y)
{
    int lca=LCA(x,y);
    sol=-INF;
    getMax(x,lca);
    getMax(y,lca);
    return sol;
}
int main()
{
    int q;
    in>>n>>q;
    adj=vector< vector<int> > (n+1);
    T2=lvl=parent=firstNode=comp=pathPos=v=vector<int> (n+1);
    tree=vector<int> (4*n+1);
    for(int i=1;i<=n;i++)
        in>>v[i];
    for(int i=2;i<=n;i++)
    {
        int x,y;
        in>>x>>y;
        adj[x].pb(y);
        adj[y].pb(x);
    }
    dfs(1,0,0,0);
    comp[0]=-1;
    int t=0;
    while(!leafs.empty())
    {
        np++;
        int x,nr=0;
        for(x=leafs.top().second;comp[x]==0;x=parent[x])
            nr++;
        for(int i=nr,x=leafs.top().second;comp[x]==0;x=parent[x],i--)
        {
            pathUpd(1,1,n,i+t,v[x]);
            comp[x]=np;
            firstNode[np]=x;
            pathPos[x]=i+t;
        }
        t+=nr;
        leafs.pop();
    }
    for(;q;q--)
    {
        int x,y,t;
        in>>t>>x>>y;
        if(t==0)
            update(x,y);
        else
            out<<query(x,y)<<'\n';
    }
    return 0;
}