/*
5 5
5 1 2 3 4 3 1 2 1 4 3 5 3
2 4 5
*/
#include<iostream>
#include<cstdio>
#include<algorithm>
#include <string.h>
#include <math.h>
#define N 80005
using namespace std;

struct Edge{
    int u,v,next;
}edge[2*N];
int head[N];
int deep[2*N];
int vis[N];
int first[N];
int ver[2*N];
int father[N];
int dp[2*N][25];
int value[N];
int path[N];
int tot;


void add_edge(int u,int v,int &k){  ///Á´Ê½Ç°ÏòÐÇ
    edge[k].u = u,edge[k].v = v;
    edge[k].next = head[u];head[u] = k++;
}
void dfs(int u,int dep,int pre){
    vis[u]=true,ver[++tot]=u,first[u]=tot,deep[tot]=dep,father[u]=pre;
    for(int k=head[u];k!=-1;k=edge[k].next){
        if(!vis[edge[k].v]){
            dfs(edge[k].v,dep+1,u);
            ver[++tot] = u,deep[tot]=dep;
        }
    }
}
int MIN(int i,int j){
    if(deep[i]<deep[j]) return i;
    return j;
}
void init_RMQ(int n){
    for(int i=1;i<=n;i++) dp[i][0]=i;
    for(int j=1;(1<<j)<=n;j++){
        for(int i=1;i+(1<<j)-1<=n;i++){
            dp[i][j] = MIN(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);
        }
    }
}
int RMQ(int L,int R){
    int k = (int)(log(R-L+1.0)/log(2.0));
    int a = dp[L][k];
    int b = dp[R-(1<<k)+1][k];
    return MIN(a,b);
}
int LCA(int a,int b){
    int x = first[a],y = first[b];
    //printf("%d %d\n",deep[x],deep[y]);
    if(x>y) swap(x,y);
    //printf("RMQ(x,y): %d\n",RMQ(x,y));
    return ver[RMQ(x,y)];
}
int cmp(int a,int b){
    return a>b;
}
void solve(int k,int u,int v){
    int lca = LCA(u,v);
    tot=0;
    while(u!=lca){
        path[tot++] = value[u];
        u = father[u];
    }
    while(v!=lca){
        path[tot++] = value[v];
        v = father[v];
    }
    //printf("lca = %d\n",lca);
    path[tot++] = value[lca];
    //printf("path[tot-1] = %d\n",path[tot-1]);
    if(k>tot){
        printf("invalid request!\n");
        return;
    }
    sort(path,path+tot,cmp);
    //for(int i=0;i<tot;i++) printf("%d ",path[i]);
    printf("%d\n",path[k-1]);
}
int main()
{
    int n,m;
    while(scanf("%d%d",&n,&m)!=EOF){
        memset(head,-1,sizeof(head));
        memset(father,-1,sizeof(father));
        for(int i=1;i<=n;i++){
            scanf("%d",&value[i]);
        }
        tot = 0;
        for(int i=1;i<n;i++){
            int u,v;
            scanf("%d%d",&u,&v);
            add_edge(u,v,tot);
            add_edge(v,u,tot);
        }
        tot = 0;
        dfs(1,1,-1);
        init_RMQ(2*n-1);
        while(m--){
            int k,a,b;
            scanf("%d%d%d",&k,&a,&b);
            if(k==0){
                value[a]=b;
            }else{
                solve(k,a,b);
            }
        }
    }
    return 0;
}