#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

ifstream f("arbint.in");
ofstream g("arbint.out");

const int NMax = 100002;
int n, arb[4 * NMax], q, maxx;

void Update(int node, int st, int dr, int pos, int val)
{
    if(st == dr)
    {
        arb[node] = val;
        return;
    }

    int m = (st + dr) >> 1;
    if(m < pos) Update(2 * node + 1, m + 1, dr, pos, val);
    else Update(2 * node, st, m, pos, val);

    arb[node] = max(arb[2 * node], arb[2 * node + 1]);
}

void Query(int node, int st, int dr, int left, int right)
{
    if(left <= st && right >= dr)
    {
        maxx = max(arb[node], maxx);
        return;
    }

    int m = (st + dr) >> 1;
    if(m >= left) Query(2 * node, st, m, left, right);
    if(m < right) Query(2 * node + 1, m + 1, dr, left, right);


}

int main()
{
    int a, b, t, x;
    f >> n >> q;
    for(int i = 1; i <= n; ++i)
    {
        f >> x;
        Update(1, 1, n, i, x);
    }
    for(int i = 1; i <= q; ++i)
    {
        f >> t >> a >> b;
        if(t) Update(1, 1, n, a, b);
        else
        {
            maxx = -1;
            Query(1, 1, n, a, b);
            g << maxx << '\n';
        }
    }
}