#include <bits/stdc++.h>
#define N_MAX 100001
using namespace std;

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

int n, m;
int tree[4 * N_MAX];

void update(int node, int left, int right, int pos, int val)
{
    if (left == right)
    {
        tree[node] = val;
        return;
    }
    int mid = (left + right) / 2;
    if (pos <= mid)
        update(2 * node, left, mid, pos, val);
    else
        update(2 * node + 1, mid + 1, right, pos, val);

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

void query(int node, int left, int right, int a, int b, int &MI)
{
    if (a <= left && right <= b)
    {
        MI = max(MI, tree[node]);
        return;
    }
    int mid = (left + right) / 2;
    if (a <= mid)
        query(2 * node, left, mid, a, b, MI);
    if (b > mid)
        query(2 * node + 1, mid + 1, right, a, b, MI);
}

int main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        int x;
        fin >> x;
        update(1, 1, n, i, x);
    }
    while (m--)
    {
        int t, x, y;
        fin >> t >> x >> y;
        if (t == 1)
        {
            update(1, 1, n, x, y);
        }
        else
        {
            int rez = -1;
            query(1, 1, n, x, y, rez);
            fout << rez << "\n";
        }
    }
    return 0;
}