#include <bits/stdc++.h>

using namespace std;

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

const int Nmax = 1e5 + 1;

int n, m;
int a[Nmax], aint[4 * Nmax];

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 x, int y)
{
    if(st == dr)
    {
        aint[nod] = y;
        return;
    }

    int mid = (st + dr) / 2;

    if(x <= mid) Update(2 * nod, st, mid, x, y);
    else Update(2 * nod + 1, mid + 1, dr, x, y);

    aint[nod] = max(aint[2 * nod], aint[2 * nod + 1]);
}

int Query(int nod, int st, int dr, int x, int y)
{
    if(x <= st && dr <= y)
        return aint[nod];

    int mid = (st + dr) / 2;
    int ans = -1;

    if(x <= mid) ans = max(ans, Query(2 * nod, st, mid, x, y));
    if(y > mid) ans = max(ans, Query(2 * nod + 1, mid + 1, dr, x, y));

    return ans;
}

int main()
{
    fin >> n >> m;

    for(int i = 1; i <= n; i++)
        fin >> a[i];

    Build(1, 1, n);
    int op, x, y;
    while(m--)
    {
        fin >> op >> x >> y;

        if(op == 1) Update(1, 1, n, x, y);
        else fout << Query(1, 1, n, x, y) << "\n";
    }

    fin.close();
    fout.close();
    return 0;
}