#include <bits/stdc++.h>

using namespace std;
const int NMAX = 100005;
ifstream fin("arbint.in");
ofstream fout("arbint.out");

int aint[4 * NMAX];
int a[NMAX];
int n, m;
int maxim = -1;

int Leftson(int node)
{
    return 2 * node;
}
int Rightson(int node)
{
    return 2 * node + 1;
}
void Build(int node, int left, int right, int poz)
{
    if(left == right)
    {
        aint[node] = a[poz];
        return;
    }
    int mid = (left + right) / 2;
    if(mid >= poz)
        Build(Leftson(node), left, mid, poz);
    else
        Build(Rightson(node), mid + 1, right, poz);
    aint[node] = max(aint[Leftson(node)], aint[Rightson(node)]);
}
void Update(int node, int left, int right, int poz, int val)
{
    if(left == right)
    {
        aint[node] = val;
        a[poz] = val;
        return;
    }
    int mid = (left + right) / 2;
    if(mid >= poz)
        Update(Leftson(node), left, mid, poz, val);
    else
        Update(Rightson(node), mid + 1, right, poz, val);
    aint[node] = max(aint[Leftson(node)], aint[Rightson(node)]);
}
void Query(int node, int left, int right, int a, int b)
{
    ///cout << left << " " << right << " " << node << "\n";
    if(a <= left && right <= b)
    {
        maxim = max(maxim, aint[node]);
        return;
    }
    int mid = (left + right) / 2;
    if(a <= mid)
        Query(Leftson(node), left, mid, a, b);
    if(b > mid)
        Query(Rightson(node), mid + 1, right, a, b);

}

int main()
{
    int i;
    fin >> n >> m;
    for(i = 1;i <= n;i++)
        fin >> a[i];
    for(i = 1;i <= n;i++)
        Build(1, 1, n, i);
    for(i = 1;i <= m;i++)
    {
        int op, x, y;
        fin >> op >> x >> y;
        if(op == 0)
        {
            maxim = -1;
            Query(1, 1, n, x, y);
            fout << maxim << "\n";
        }
        else
        {
            Update(1, 1, n, x, y);
        }
    }
    return 0;
}