#include <fstream>
#include <vector>
using namespace std;
ifstream in("heavypath.in");
ofstream out("heavypath.out");
vector <int> v[100005];
int n,m,i,must,mudr,chain,lvl[100005],si[100005],maf[100005],cnt[100005],pos[100005],id[100005],first[100005],val[100005],tata[100005],cer;
int **ar;
void dfs(int nod,int ta,int lv)
{
    lvl[nod]=lv;
    si[nod]=1;
    for (int i=0;i<v[nod].size();++i)
    {
        if (v[nod][i]!=ta) {
        dfs(v[nod][i],nod,lv+1);
        si[nod]+=si[v[nod][i]];
        if (si[v[nod][i]]>si[maf[nod]])
            maf[nod]=v[nod][i];}
            else {tata[nod]=v[nod][i];}
    }
}
void split(int nod,int ta)
{
    id[nod]=chain;
    pos[nod]=++cnt[chain];
    if (cnt[chain]==1)
        first[chain]=nod;
    if (si[nod]==1)
        return ;
    split(maf[nod],nod);
    for (int i=0;i<v[nod].size();++i)
    {
        if (v[nod][i]!=ta&&v[nod][i]!=maf[nod])
        {
            ++chain;
            split(v[nod][i],nod);
        }
    }
}
void update (int st,int dr,int nod,int pos,int val,int chan)
{
    if (st==dr)
    {
    ar[chan][nod]=val;
    return ;
    }
    int mij=(st+dr)/2;
    if (pos<=mij) update(st,mij,nod*2,pos,val,chan);
    else update(mij+1,dr,nod*2+1,pos,val,chan);
    ar[chan][nod]=max(ar[chan][nod*2],ar[chan][nod*2+1]);
}
void upnod (int nod,int va)
{
    val[nod]=va;
    update(1,cnt[id[nod]],1,pos[nod],val[nod],id[nod]);
}
int query(int st,int dr,int nod,int qa,int qb,int chan)
{
    if (qa<=st&&qb>=dr)
        return ar[chan][nod];
    int mij=(st+dr)/2,ras1=0,ras2=0;
    if (qa<=mij) ras1=query(st,mij,nod*2,qa,qb,chan);
    if (qb>mij) ras2=query(mij+1,dr,nod*2+1,qa,qb,chan);
    return max(ras1,ras2);
}
int qunod(int st,int dr)
{
    if (id[st]==id[dr])
    {
        return query(1,cnt[id[st]],1,min(pos[st],pos[dr]),max(pos[st],pos[dr]),id[st]);
    }
    if (lvl[first[id[st]]]>=lvl[first[id[dr]]])
    {
        return max(qunod(st,first[id[st]]),qunod(tata[first[id[st]]],dr));
    }
    else
    {
        return max(qunod(dr,first[id[dr]]),qunod(tata[first[id[dr]]],st));
    }
}
int main()
{
    in>>n>>m;
    for (i=1;i<=n;++i)
    {
        in>>val[i];
    }
    for (i=1;i<=n-1;++i)
    {
        in>>must>>mudr;
        v[must].push_back(mudr);
        v[mudr].push_back(must);
    }
    dfs(1,0,1);
    chain=1;
    split(1,0);
    ar=new int *[chain+1];
    for (i=1;i<=chain;++i)
    {
        ar[i]=new int [4*(cnt[chain]+1)+1];
    }
    for (i=1;i<=n;++i)
    {
        upnod(i,val[i]);
    }
    for (i=1;i<=m;++i)
    {
        in>>cer>>must>>mudr;
        if (cer==0) {upnod(must,mudr);}
        else {out<<qunod(must,mudr)<<'\n';}
    }
    return 0;
}