#include <bits/stdc++.h>
using namespace std;

const string FILENAME = "arbint";

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


int n, m;
int a[4 * 100001];

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

void update(int nod, int st, int dr, int p, int val)
{
    if(st == dr)
        a[nod] = val;
    else
    {
        int mid = (st + dr) >> 1;
        if(p <= mid)
            update(nod << 1, st ,mid, p ,val);
        else update(nod << 1 | 1, mid + 1, dr, p , val);
        a[nod] = max(a[nod << 1], a[nod << 1 | 1]);
    }
    
}

int query(int nod, int st, int dr, int x, int y)
{
    if(st > dr || st > y || dr < x)
        return -1;
    if(st >= x && dr <= y)
        return a[nod];
    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()
{
    int op, 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;
}