#include <bits/stdc++.h>
using namespace std;
ifstream in("arbint.in");
ofstream out("arbint.out");
const int NMAX = 1e5 + 5;
int n, m;
int tree[NMAX * 4];
int val, pos, maxi;
int q, a, b;

void build(int node, int l, int r)
{
    if(l == r)
    {
        in >> tree[node];
        return;
    }

    int m = (l + r) / 2;

    build(node * 2, l, m);
    build(node * 2 + 1, m + 1, r);

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

void update(int node, int l, int r, int a, int b)
{
    if(l == r)
    {
        tree[node] = b;
        return;
    }

    int m = (l + r) / 2;

    if(a <= m)
        update(2 * node, l, m, a, b);

    if(a > m)
        update(2 * node + 1, m + 1, r, a, b);

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

void query(int node, int l, int r, int a, int b)
{
    if(a <= l && r <= b)
    {
        maxi = max(maxi, tree[node]);
        return;
    }

    int m = (l + r) / 2;

    if(a <= m)
    {
        query(node * 2, l, m, a, b);
    }

    if(b > m)
    {
        query(node * 2 + 1, m + 1, r, a, b);
    }
}

int main()
{
    in >> n >> m;

    build(1, 1, n);

    for(int i = 1; i <= m; ++i)
    {
        in >> q >> a >> b;

        if(q == 0)
        {
            maxi = -1;

            query(1, 1, n, a, b);

            out << maxi << '\n';
        }
        else
        {
            update(1, 1, n, a, b);
        }
    }
    return 0;
}