#include <fstream>
#include <vector>
#define mid (l+r)/2

using namespace std;

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

const int NMAX=1e5+5, LMAX=17;
int n, m, val[NMAX], p[NMAX], d[NMAX], hc[NMAX];
int dtime, clc=1, poz[NMAX], lc[NMAX];
vector<int> adj[NMAX];

struct AINT
{
    int aint[4*NMAX];
    
    void update(int nod, int l, int r, int &poz, int &val)
    {
        if(poz<l || r<poz)
            return;
        if(l==r)
        {
            aint[nod]=val;
            return;
        }
        update(2*nod, l, mid, poz, val);
        update(2*nod+1, mid+1, r, poz, val);
        aint[nod]=max(aint[2*nod], aint[2*nod+1]);
    }
    
    int query(int nod, int l, int r, int &ql, int &qr)
    {
        if(qr<l || r<ql)
            return 0;
        if(ql<=l && r<=qr)
            return aint[nod];
        return max(query(2*nod, l, mid, ql, qr),
                   query(2*nod+1, mid+1, r, ql, qr));
    }
}ds;

int DFS(int u)
{
    int maxsz=0, szu=1, szv;
    for(auto v:adj[u])
        if(v!=p[u])
        {
            d[v]=d[u]+1; p[v]=u;
            szv=DFS(v);
            szu+=szv;
            if(szv>maxsz)
            {
                maxsz=szv;
                hc[u]=v;
            }
        }
    return szu;
}

void DFSord(int u)
{
    dtime++; poz[u]=dtime; lc[u]=clc;
    ds.update(1, 1, n, dtime, val[u]);
    
    if(hc[u]>0)
        DFSord(hc[u]);
    for(auto v:adj[u])
        if(v!=p[u] && v!=hc[u])
        {
            clc=v;
            DFSord(v);
        }
}

int hvquery(int u, int v)
{
    int ans=0;
    while(lc[u]!=lc[v])
    {
        if(d[lc[u]]>d[lc[v]])
            swap(u, v);
        ans=max(ans, ds.query(1, 1, n, poz[lc[v]], poz[v]));
        v=p[lc[v]];
    }
    if(d[u]>d[v])
        swap(u, v);
    ans=max(ans, ds.query(1, 1, n, poz[u], poz[v]));
    return ans;
}

int main()
{
    in>>n>>m;
    for(int i=1;i<=n;i++)
        in>>val[i];
    for(int i=1;i<n;i++)
    {
        int a, b; in>>a>>b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    
    DFS(1);
    DFSord(1);
    while(m--)
    {
        int t, x, y;
        in>>t>>x>>y;
        if(t==0)
            ds.update(1, 1, n, poz[x], y);
        else
            out<<hvquery(x, y)<<'\n';
    }
    return 0;
}