#include <bits/stdc++.h>

using namespace std;

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

const int nmax = 100005;
int aint[4 * nmax], a[nmax], ans;
int n, m;
void Build(int nod, int st, int dr)
{
    if(st == dr)
    {
        aint[nod] = a[st];
        return;
    }
    int mid = (st + dr) / 2;
    Build(2 * nod, st, mid);
    Build(2 * nod + 1, mid + 1, dr);
    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}
void Update(int nod, int st, int dr, int poz, int val)
{
    if(st == dr)
    {
        aint[nod] = val;
        return;
    }
    int mid = (st + dr) / 2;
    if(poz <= mid)
        Update(2 * nod, st, mid, poz, val);
    else
        Update(2 * nod + 1, mid + 1, dr, poz, val);
    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}
void Query(int nod, int st, int dr, int lquery, int rquery)
{
    if(lquery <= st && rquery >= dr)
    {
        ans = max(ans, aint[nod]);
        return;
    }
    int mid = (st + dr) / 2;
    if(lquery <= mid)
        Query(2 * nod, st, mid, lquery, rquery);
    if(rquery > mid)
        Query(2 * nod + 1, mid + 1, dr, lquery, rquery);
}
void Citire()
{
    int i, op, x, y;
    fin >> n >> m;
    for(i = 1;i <= n;i++)
        fin >> a[i];
    Build(1, 1, n);
    for(i = 1;i <= m;i++)
    {
        fin >> op >> x >> y;
        if(op == 1)
            Update(1, 1, n, x, y);
        else
        {
            ans = -1;
            Query(1, 1, n, x, y);
            fout << ans << "\n";
        }
    }
}

int main()
{
    Citire();
    return 0;
}