#include <bits/stdc++.h>
using namespace std;
ifstream fin ("arbint.in");
ofstream fout ("arbint.out");
#define N_MAX 100003
int N, M, val, a, b, poz;
int Arbore [4 * N_MAX];
void Update (int nod, int st, int dr, int poz, int val){
    if (st == dr){
        Arbore [nod] = val;
        return;
    }
    else{
        int med = (st + dr) / 2;
        if (poz <= med)
            Update (2 * nod, st, med, poz, val);
        else
            Update ((2 * nod) + 1, med + 1, dr, poz, val);

        Arbore [nod] = max (Arbore [2 * nod], Arbore [(2 * nod) + 1]);
    }
}
int Query (int nod, int st, int dr, int qdr, int qst){
    if (dr < qdr || st > qst)
        return 0;
    if (qdr <= st && dr <= qst)
        return Arbore [nod];
    else{
        int med = (st + dr) / 2;
        int q1 = Query (2 * nod, st, med, qdr, qst);
        int q2 = Query ((2 * nod) + 1, med + 1, dr, qdr, qst);
        return max (q1, q2);
    }
}
int main(){
    fin >> N >> M;
    for(int i = 1; i <= N; i++){
        fin >> val;
        Update (1, 1, N, i, val);
    }
    for(int i = 1, type; i <= M; i++){
        fin >> type;
        if (type != 0){
            fin >> poz >> val;
            Update (1, 1, N, poz, val);
        }
        else{
            fin >> a >> b;
            fout << Query (1, 1, N, a, b) << '\n';
        }
    }
    return 0;
}