#include <iostream>
#include <fstream>
using namespace std;

const int nmax =  400070;

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

int Arb[nmax];
int n, m;
int Begin, End, val, pos, maxim;

#define Max(a, b) ((a >b) ? a : b)

void actualizare(int nod, int l, int r)
{
    if(l == r)
    {
        Arb[nod] = val;
        return;
    }
    int mij=(l + r) / 2;
    if (pos <= mij)
        actualizare(2 * nod, l , mij);
    else actualizare(2 * nod + 1, mij + 1, r);
    Arb[nod]= Max(Arb[2 * nod], Arb [2 * nod +1]);
}

void interogare(int nod, int l, int r)
{
    if(Begin <= l && r <= End){
        if(maxim < Arb[nod])
            maxim = Arb[nod];
        return;
    }
    int mij = (l + r) / 2;
    if (Begin <= mij)
        interogare(2 *nod, l, mij);
    if(mij < End)
        interogare(2* nod +1, mij + 1, r);
}

int main()
{
    int a, b, x;
    fin >> n >> m;
    for(int i = 1; i<= n; ++i)
    {
        fin >> x;
        pos = i;
        val = x;
        actualizare (1, 1, n);
    }
    for (int i = 1; i <= m; ++i)
    {
        fin >> x >> a >> b;
        if (x == 0)
        {
            maxim = -1;
            Begin = a ;
            End = b;
            interogare(1, 1, n);
            fout << maxim << ' ';
            fout << endl;
        }
        else {
            pos = a;
            val = b;
            actualizare(1, 1, n);
        }
    }
    return 0;
}