#include <bits/stdc++.h>

using namespace std;

const string FILENAME = "arbint";

ifstream fin(FILENAME + ".in");
ofstream fout(FILENAME + ".out");

int n, m;
int arb[4 * 100000 + 1];

void build(int nod, int st, int dr)
{
    if(st == dr)
        fin >> arb[nod];
    else
    {
        int mid = (st + dr) >> 1;
        build(nod << 1, st, mid);
        build(nod << 1 | 1 , mid + 1, dr);
        arb[nod] = max(arb[nod << 1], arb[nod << 1 | 1]);
    }    
}

void update(int nod, int st, int dr, int p, int x)
{
    if(st == dr)
        arb[nod] = x;
    else 
    {
        int mid = (st + dr)>> 1;
        if(p <= mid)
            update(nod << 1, st ,mid, p, x);
        else update(nod << 1 | 1, mid + 1 , dr, p , x);
        arb[nod] = max(arb[nod << 1], arb[nod << 1 | 1]);
    }
}
int query(int nod, int st, int dr, int x, int y)
{
    if( st > y || dr < x)
        return -1;
    else if(st >= x && dr <= y)
        return arb[nod];
    else
    {
        int mid = (st + dr) >> 1;
        int q1 = query(nod << 1, st ,mid, x, y);
        int q2 = query(nod << 1 | 1, mid + 1, dr, x, y);
        return max(q1, q2);
    }
    
}
int main()
{
    short op;
    int x, y;
    fin >> n >> m;
    build(1, 1, n);
    while(m--)
    {
        fin >> op >> x >> y;
        if(op == 0)
            fout << query(1, 1, n, x, y) << "\n";
        else update(1, 1, n, x, y);
    }
    fin.close();
    fout.close();
    return 0;
}