#include <fstream>

using namespace std;

const int N = 1 << 18;
const int INF = 1 << 30;

int arbint[N];

ifstream in("arbint.in");
ofstream out("arbint.out");

void constructie(int p, int st, int dr)
{
    if (st == dr)
    {
        in >> arbint[p];
        return;
    }
    int m = (st + dr) / 2, fs = 2 * p, fd = 2 * p + 1;
    constructie(fs, st, m);
    constructie(fd, m + 1, dr);
    arbint[p] = max(arbint[fs], arbint[fd]);
}

int interogare(int p, int st, int dr, int a, int b)
{
    ///apelul curent (+cele subordonate) va determina max(v[a1],v[a1+1],...,v[b1])
    ///unde [a1,b1] = [st,dr] intersectat cu [a,b]
    if (a <= st && dr <= b)///intersectia e chiar [st,dr]
    {
        return arbint[p];
    }
    int m = (st + dr) / 2, fs = 2 * p, fd = 2 * p + 1;
    int rez_st = -INF, rez_dr = -INF;
    if (a <= m)///intervalul asociat fiului stang se intersecteaza cu [a,b]
    {
        rez_st = interogare(fs, st, m, a, b);
    }
    if (m + 1 <= b)///intervalul asociat fiului drept se intersecteaza cu [a,b]
    {
        rez_dr = interogare(fd, m + 1, dr, a, b);
    }
    return max(rez_st, rez_dr);
}

void actualizare(int p, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        arbint[p] = val;
        return;
    }
    int m = (st + dr) / 2, fs = 2 * p, fd = 2 * p + 1;
    if (poz <= m)///actualizarea il afecteaza pe fiul stang
    {
        actualizare(fs, st, m, poz, val);
    }
    else
    {
        actualizare(fd, m + 1, dr, poz, val);
    }
    arbint[p] = max(arbint[fs], arbint[fd]);
}

int main()
{
    int n, nq;
    in >> n >> nq;
    constructie(1, 1, n);
    for (int i = 0; i < nq; i++)
    {
        int tip;
        in >> tip;
        if (tip == 0)
        {
            int a, b;
            in >> a >> b;
            out << interogare(1, 1, n, a, b) << "\n";
        }
        else
        {
            int poz, val;
            in >> poz >> val;
            actualizare(1, 1, n, poz, val);
        }
    }
    in.close();
    out.close();
    return 0;
}