#include <iostream>
#include <fstream>
#include <vector>

#pragma GCC optimize("Ofast")

using namespace std;

class InParser {
private:
	FILE *fin;
	char *buff;
	int sp;

	char read_ch() {
		++sp;
		if (sp == 4096) {
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}

public:
	InParser(const char* nume) {
		fin = fopen(nume, "r");
		buff = new char[4096]();
		sp = 4095;
	}
	
	InParser& operator >> (int &n) {
		char c;
		while (!isdigit(c = read_ch()) && c != '-');
		int sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
	
	InParser& operator >> (long long &n) {
		char c;
		n = 0;
		while (!isdigit(c = read_ch()) && c != '-');
		long long sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
};

class OutParser {
private:
    FILE *fout;
    char *buff;
    int sp;
 
    void write_ch(char ch) {
        if (sp == 50000) {
            fwrite(buff, 1, 50000, fout);
            sp = 0;
            buff[sp++] = ch;
        } else {
            buff[sp++] = ch;
        }
    }
 
 
public:
    OutParser(const char* name) {
        fout = fopen(name, "w");
        buff = new char[50000]();
        sp = 0;
    }
    ~OutParser() {
        fwrite(buff, 1, sp, fout);
        fclose(fout);
    }
 
    OutParser& operator << (int vu32) {
        if (vu32 <= 9) {
            write_ch(vu32 + '0');
        } else {
            (*this) << (vu32 / 10);
            write_ch(vu32 % 10 + '0');
        }
        return *this;
    }
 
    OutParser& operator << (long long vu64) {
        if (vu64 <= 9) {
            write_ch(vu64 + '0');
        } else {
            (*this) << (vu64 / 10);
            write_ch(vu64 % 10 + '0');
        }
        return *this;
    }
 
    OutParser& operator << (char ch) {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch) {
        while (*ch) {
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};

const int NMAX = 1e5;

int n, q;
int v[NMAX + 1];
int sz[NMAX + 1];
int parent[NMAX + 1];
int level[NMAX + 1];

int heavyChild[NMAX + 1];

vector <int> adj[NMAX + 1];

void explore(int node, int Parent){
    sz[node] = 1;

    parent[node] = Parent;
    level[node] = level[Parent] + 1;

    int maxi = 0;
    for(int child : adj[node]){
        if(child != Parent){
            explore(child, node);
            sz[node] += sz[child];

            if(sz[child] > maxi){
                maxi = sz[child];
                heavyChild[node] = child;
            }
        }
    }
}

int Id = 0;
int id[NMAX + 1];
int head[NMAX + 1];

int dfsTime = 0;
int lin[NMAX + 1];
int Time[NMAX + 1];

void heavyFirstLin(int node, int Parent){
    ++dfsTime;
    lin[dfsTime] = node;
    Time[node] = dfsTime;

    if(heavyChild[Parent] == node){
        id[node] = id[Parent];
    }else{
        id[node] = ++Id;
        head[Id] = node;
    }

    if(heavyChild[node] != 0){
        heavyFirstLin(heavyChild[node], node);
    }

    for(int child : adj[node]){
        if(child != Parent && child != heavyChild[node]){
            heavyFirstLin(child, node);
        }
    }
}

namespace SegTree{
    int aint[4 * NMAX + 1];

    void build(int node, int left, int right){
        if(left == right){
            aint[node] = v[lin[left]];
            return;
        }

        int mij = (left + right) / 2;
        build(2 * node, left, mij);
        build(2 * node + 1, mij + 1, right);

        aint[node] = max(aint[2 * node], aint[2 * node + 1]);
    }

    void update(int node, int left, int right, int pos, int val){
        if(left == right){
            aint[node] = val;
            return;
        }

        int mij = (left + right) / 2;
        if(pos <= mij){
            update(2 * node, left, mij, pos, val);
        }else{
            update(2 * node + 1, mij + 1, right, pos, val);
        }

        aint[node] = max(aint[2 * node], aint[2 * node + 1]);
    }

    int query(int node, int left, int right, int qLeft, int qRight){
        if(qLeft <= left && right <= qRight){
            return aint[node];
        }

        int mij = (left + right) / 2;

        int ans = 0;

        if(qLeft <= mij){
            ans = max(ans, query(2 * node, left, mij, qLeft, qRight));
        }

        if(mij + 1 <= qRight){
            ans = max(ans, query(2 * node + 1, mij + 1, right, qLeft, qRight));
        }

        return ans;
    }
}

int query(int a, int b){
    int ans = 0;

    while(id[a] != id[b]){
        if(level[head[id[a]]] > level[head[id[b]]]){
            ans = max(ans, SegTree::query(1, 1, n, Time[head[id[a]]], Time[a]));
            a = parent[head[id[a]]];
        }else{
            ans = max(ans, SegTree::query(1, 1, n, Time[head[id[b]]], Time[b]));
            b = parent[head[id[b]]];
        }
    }

    ans = max(ans, SegTree::query(1, 1, n, min(Time[a], Time[b]), max(Time[a], Time[b])));

    return ans;
}

int main(){

    InParser fin("heavypath.in");
    OutParser fout("heavypath.out");

    fin >> n >> q;

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

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

    explore(1, 0);
    heavyFirstLin(1, 0);
    SegTree::build(1, 1, n);

    while(q--){
        int type, x, y;
        fin >> type >> x >> y;

        if(type == 0){
            SegTree::update(1, 1, n, Time[x], y);
        }else{
            fout << query(x, y) << '\n';
        }
    }

    return 0;
}