#include <bits/stdc++.h>

#define N_MAX 100005

using namespace std;

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

int N, M;
int tree[4 * N_MAX];

void update(int node, int le, int ri, int pos, int val)
{
    if(le == ri) {
        tree[node] = val;
        return;
    }

    int mid = (le + ri) / 2;
    if(pos <= mid) {
        update(2 * node, le, mid, pos, val);
    }
    else {
        update(2 * node + 1, mid + 1, ri, pos, val);
    }

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

void query(int node, int le, int ri, int a, int b, int &MI)
{
    if(a <= le && ri <= b) {
        MI = max(MI, tree[node]);
        return;
    }

    int mid = (le + ri) / 2;
    if(a <= mid) {
        query(2 * node, le, mid, a, b, MI);
    }
    if(b > mid) {
        query(2 * node + 1, mid + 1, ri, a, b, MI);
    }
}

int main()
{
    f >> N >> M;
    for(int i = 1; i <= N; i++) {
        int x;
        f >> x;
        update(1, 1, N, i, x);
    }

    while(M--) {
        int t, x, y;
        f >> t >> x >> y;
        if(t == 1) {
            update(1, 1, N, x, y);
        }
        else {
            int ans = -1;
            query(1, 1, N, x, y, ans);
            g << ans << "\n";
        }
    }
    return 0;
}