#include <bits/stdc++.h>
using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");
int n, m;
int x, y, z;
int arbore[4 * 100005];
int maxim;
void Update(int nod, int stanga, int dreapta, int pos, int val)
{
    if(stanga == dreapta)
    {
        arbore[nod] = val;
        return;
    }

    int mid = (stanga + dreapta) / 2;
    if(pos <= mid)
        Update(2 * nod, stanga, mid, pos, val);
    else
        Update(2 * nod + 1, mid + 1, dreapta, pos, val);

    arbore[nod] = max(arbore[2 * nod], arbore[2 * nod + 1]);
}
void Query(int nod, int stanga, int dreapta, int start, int finish)
{
    if(start <= stanga && dreapta <= finish)
    {
        maxim = max(maxim, arbore[nod]);
        return;
    }

    int mid = (stanga + dreapta) / 2;
    if(start <= mid)
        Query(2 * nod, stanga, mid, start, finish);
    if(mid < finish)
        Query(2 * nod + 1, mid + 1, dreapta, start, finish);
}
void Read()
{
    f>>n>>m;
    for(int i = 1;i <= n;++i)
    {
        f>>x;
        Update(1, 1, n, i, x);
    }
}
void Solve()
{
    for(int i = 1;i <= m;++i)
    {
        f>>x>>y>>z;
        if(!x)
        {
            maxim = -1;
            Query(1, 1, n, y, z);

            g<<maxim<<'\n';
        }
        else
            Update(1, 1, n, y, z);
    }
}

int main()
{
    Read();
    Solve();
    return 0;
}