#include <iostream>
#include <fstream>

using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");

const int N = 1 << 18, INF = 1;
int n, q, t[N], a, b, poz, val;

void actualizare(int p, int st, int dr)
{
    //out << "d" << " ";
    if(st == dr){
        t[p] = val;
        return;
    }
    int m = (st + dr) / 2;
    if(poz <= m){
        actualizare(2 * p, st, m);
    }
    else{
        actualizare(2 * p + 1, m + 1, dr);
    }
    t[p] = max(t[2 * p], t[2 * p + 1]);
}

int interogare(int p, int st, int dr)
{
    //out << "a";
    if(a <= st && dr <= b){
        return t[p];
    }
    int m = (st + dr) / 2, mst = -INF, mdr = -INF;
    if(a <= m){
        mst = interogare(2 * p, st, m);
    }
    if(b > m){
        mdr = interogare(2 * p + 1, m + 1, dr);
    }
    return max(mst,mdr);
}

int main()
{
    in >> n >> q;
    for(int i = 1; i <= n; i++){
        in >> val;
        poz = i;
        actualizare(1, 1, n);
        //out << i << " ";
    }
    //out << "trecut";
    while(q--){
        int code;
        in >> code;
        //out << code << "\n";
        if(code == 0){
            in >> a >> b;
            int m = interogare(1, 1, n);
            out << m << "\n";
        }
        else{
            in >> poz >> val;
            actualizare(1, 1, n);
        }
    }

    return 0;
}