#include <iostream>
#include <fstream>

#define nmax 100001

using namespace std;

ifstream fi("arbint.in");
ofstream fo("arbint.out");

int n, m;
int x, a, b, maxim;
bool t;
int ARB[4*nmax];

void update(int nod, int st, int dr, int pos, int val)
{

    if (st == dr)
    {
        ARB[nod] = val;
        return;
    }

    int mid = (st + dr) >> 1;

    if (pos <= mid) update(2*nod, st, mid, pos, val);
    else            update(2*nod+1, mid+1, dr, pos, val);

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

}

void query(int nod, int st, int dr, int start, int finish)
{

    if (start <= st && dr <= finish)
    {
        maxim = max(maxim, ARB[nod]);
        return;
    }

    int mid = (st + dr) >> 1;

    if (start <= mid) query(2*nod, st, mid, start, finish);
    if (finish > mid) query(2*nod+1, mid+1, dr, start, finish);

}

int main()
{

    fi >> n >> m;

    for (int i = 1; i <= n; i++)
        fi >> x,
        update(1, 1, n, i, x);

    for (int i = 1; i <= m; i++)
    {
        fi >> t;
        fi >> a >> b;

        if (t)
        {
            // valoarea elementului de pe pozitia a va deveni b
            update(1, 1, n, a, b);
        }
        else
        {
            // max([a, b])
            maxim = -1;
            query(1, 1, n, a, b);
            fo << maxim << "\n";
        }
    }

    fi.close();
    fo.close();

    return 0;
}