#include <bits/stdc++.h>

using namespace std;
ifstream f("heavypath.in");
ofstream g("heavypath.out");
int mar[200005],tata[200005],poz[200005],cnt[200005],id[200005],max_fiu[200005],niv[200005];
vector <int> v[200005];
void dfs(int x,int dad,int nivel)
{
    mar[x]=1;
    tata[x]=dad;
    niv[x]=nivel;
    for (int i=0;i<v[x].size();i++)
    {
        if (v[x][i]!=dad)
        {
            dfs(v[x][i],x,nivel+1);
            mar[x]+=mar[v[x][i]];
            if (mar[v[x][i]]>mar[max_fiu[x]])
            {
                max_fiu[x]=v[x][i];
            }
        }
    }
}
int q,prim[200005];
void solve(int x,int tata)
{
    cnt[q]++;
    poz[x]=cnt[q];
    if (poz[x]==1)
    {
        prim[q]=x;
    }
    id[x]=q;
    if (mar[x]==1)
    {
        return;
    }
    solve(max_fiu[x],x);
    for (int i=0;i<v[x].size();i++)
    {
        if (v[x][i]!=max_fiu[x]&&v[x][i]!=tata)
        {
            q++;
            solve(v[x][i],x);
        }
    }
}
int max1(int x,int y)
{
    if (x>y)
    {
        return x;
    }
    return y;
}
class SegmentTree{
    int *arb;
public:
    void Initialize(int lung)
    {
        arb=new int[(4*lung+1)];
        for (int i=1;i<=4*lung;i++)
        {
            arb[i]=0;
        }
    }
    void update(int st,int dr,int nod,int poz,int val)
    {
        if (st==dr)
        {
            arb[nod]=val;
            return;
        }
        int mij=(st+dr)/2;
        if (poz<=mij)
        {
            update(st,mij,2*nod,poz,val);
        }
        else
        {
            update(mij+1,dr,2*nod+1,poz,val);
        }
        arb[nod]=max1(arb[2*nod],arb[2*nod+1]);
    }
    int query(int st,int dr,int nod,int ua,int ub)
    {
        if (ua<=st&&dr<=ub)
        {
            return arb[nod];
        }
        int mij=(st+dr)/2;
        if (ub<=mij)
        {
            return query(st,mij,2*nod,ua,ub);
        }
        if (mij<ua)
        {
            return query(mij+1,dr,2*nod+1,ua,ub);
        }
        return max1(query(st,mij,2*nod,ua,ub),query(mij+1,dr,2*nod+1,ua,ub));
    }
}*Chains;
int query(int x,int y)
{
    if (id[x]==id[y])
    {
        int stanga,dreapta;
        stanga=min(poz[x],poz[y]);
        dreapta=max(poz[x],poz[y]);
        return Chains[id[x]].query(1,cnt[id[x]],1,stanga,dreapta);
    }
    if (niv[prim[id[x]]]>niv[prim[id[y]]])
    {
        swap(x,y);
    }
    return max1(query(y,prim[id[y]]),query(tata[prim[id[y]]],x));
}
int n,m,x,y,i,val[200005],t;
int main()
{
    f>>n>>m;
    for (i=1;i<=n;i++)
    {
        f>>val[i];
    }
    for (i=1;i<n;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1,0,1);
    q=1;
    solve(1,0);
    Chains = new SegmentTree [(q+1)];
    for (i=1;i<=q;i++)
    {
        Chains[i].Initialize(cnt[i]);
    }
    for (i=1;i<=n;i++)
    {
        Chains[id[i]].update(1,cnt[id[i]],1,poz[i],val[i]);
    }
    for (i=1;i<=m;i++)
    {
        f>>t>>x>>y;
        if (t==0)
        {
            Chains[id[x]].update(1,cnt[id[x]],1,poz[x],y);
        }
        else
        {
            g<<query(x,y)<<'\n';
        }
    }
    return 0;
}