/*Arbori de intervale
*/
#include<fstream>
#include<vector>
#include<string>
const int NMAX =  100000;

using namespace std;

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


string sir;
int i, n, k, j, m, nr, sol, x , y;
int MaxArb[2 * NMAX + 5];

void query(int nod, int stanga, int dreapta, int start, int finish)
{
    if(start <= stanga && dreapta <= finish)
    {
        sol = max(sol , MaxArb[nod]);
        return;
    }
    int mij = (stanga + dreapta) / 2;
    if(start <= mij)
    {
        query(2 * nod, stanga, mij, start, finish);
    }
    if(mij < finish)
    {
        query(2 * nod + 1,  mij + 1, dreapta, start, finish);
    }
}


void update(int nod, int stanga, int dreapta, int position, int value)
{
    //fout << nod<<"\n";
    if(stanga == dreapta)
    {
        MaxArb[nod] = value;
        return;
    }
    int mij = (stanga + dreapta) / 2;
    if(position <= mij)
    {
        update(2 * nod, stanga, mij, position, value);
    }
    else
    {
        update(2 * nod + 1, mij + 1, dreapta, position, value);
    }
    if((2 * nod) <= 2 * NMAX + 5)
        MaxArb[nod] = max( MaxArb[2 * nod], MaxArb[2 * nod + 1]);
}

int main()
{
    fin >> n >> m;
    for(i = 1; i <= n; i++)
    {
        fin >> nr;
        update(1, 1, n, i, nr);
    }
    for(i = 1; i <= m; i++)
    {
        fin >> nr >> x >> y;
        if(nr == 1)
        {
            update(1, 1, n, x, y);
        }
        else
        {
            sol =-1;
            query(1, 1, n, x, y);
            fout << sol << "\n";
        }
    }
    for(i = 1; i <= 2*n; i++)
    {
        //fout << MaxArb[i] << " ";
    }
}