#include <fstream>
#include <vector>
#include <cmath>

using namespace std;

void actualizare(vector <int> &aint, int p, int st, int dr, int poz, int val)
{
    if (st == dr)
    {
        aint[p] = val;
        return;
    }
    int m = (st + dr) / 2, fs = 2 * p, fd = 2 * p + 1;
    if (poz <= m)
    {
        actualizare(aint, fs, st, m, poz, val);
    }
    else
    {
        actualizare(aint, fd, m + 1, dr, poz, val);
    }
    aint[p] = max(aint[fs], aint[fd]);
}

int interogare(vector <int> &aint, int p, int st, int dr, int a, int b)
{
    ///returneaza max din [st, dr] intersectat cu [a, b]
    if (a <= st && dr <= b)
    {
        return aint[p];
    }
    int m = (st + dr) / 2, fs = 2 * p, fd = 2 * p + 1, rez_st = -1, rez_dr = -1;
    if (a <= m)
    {
        rez_st = interogare(aint, fs, st, m, a, b);
    }
    if (m + 1 <= b)
    {
        rez_dr = interogare(aint, fd, m + 1, dr, a, b);
    }
    return max(rez_st, rez_dr);
}

int main()
{
    ifstream in("arbint.in");
    ofstream out("arbint.out");
    int n, m;
    in >> n >> m;
    int log_sup = (int)log2(n);
    if ((1 << log_sup) < n)
    {
        log_sup++;
    }
    vector <int> aint(1 << (1 + log_sup), -1);
    for (int i = 1; i <= n; i++)
    {
        int aux;
        in >> aux;
        actualizare(aint, 1, 1, n, i, aux);
    }
    for (int i = 0; i < m; i++)
    {
        int tip;
        in >> tip;
        if (tip == 0)
        {
            int a, b;
            in >> a >> b;
            out << interogare(aint, 1, 1, n, a, b) << "\n";
        }
        else
        {
            int poz, val;
            in >> poz >> val;
            actualizare(aint, 1, 1, n, poz, val);
        }
    }
    in.close();
    out.close();
    return 0;
}