#include <fstream>
#include <vector>
#define NMAX 100002
using namespace std;
ifstream  fin("heavypath.in");
ofstream fout("heavypath.out");
int N,M,v[NMAX],nivel[NMAX],parent[NMAX];
vector<int> tree[NMAX];

void citire()
{
    fin>>N>>M;

    for(int i=1; i<=N; i++)
    {
        fin>>v[i];
    }

    int a,b;
    for(int i=1; i<N; i++)
    {
        fin>>a>>b;
        tree[a].push_back(b);
        tree[b].push_back(a);
    }
}

void DFS(int nod, int tata)
{
    nivel[nod]=nivel[tata]+1;
    parent[nod]=tata;
    for(int i=0; i<tree[nod].size(); i++)
    {
        int next_nod=tree[nod][i];

        if(next_nod!=tata)
        {
            DFS(next_nod,nod);
        }
    }
}

int lca(int x, int y)
{
    while(nivel[x]>nivel[y])
    {
        x=parent[x];
    }

    while(nivel[y]>nivel[x])
    {
        y=parent[y];
    }

    while(x!=y)
    {
        x=parent[x];
        y=parent[y];
    }

    return x;
}

int main()
{
    citire();

    DFS(1,0);

    int t,x,y;
    for(int q=1; q<=M; q++)
    {
        fin>>t>>x>>y;

        if(t==0)
        {
            v[x]=y;
        }
        else
        {
            int ans,l;
            ans=0;
            l=lca(x,y);

            while(x!=l)
            {
                ans=max(ans,v[x]);
                x=parent[x];
            }

            while(y!=l)
            {
                ans=max(ans,v[y]);
                y=parent[y];
            }

            ans=max(ans,v[l]);

            fout<< ans << "\n";
        }
    }

    return 0;
}