#include <bits/stdc++.h>
#define Nmax 100005
using namespace std;

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

int N, M;
int tree[4 * Nmax], ans;

void update(int node, int le, int ri, int pos, int val) {
    if (le == ri) tree[node] = val;
    else {
        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) {
    if (le >= a && ri <= b) ans = max(ans, tree[node]);
    else {
    int mid = (le + ri) / 2;
    if (a <= mid) query(2 * node, le, mid, a, b);
    if (mid < b) query(2 * node + 1, mid + 1, ri, a, b);
    }
}
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 tip, a, b;
        fin >> tip >> a >> b;
        if (tip == 0) {
            ans = -1;
            query(1, 1, N, a, b);
            fout << ans << '\n';
        }
        else update(1, 1, N, a, b);
    }

    return 0;
}