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

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

const int NMAX=100002;

int N,Q;
int tree[4*NMAX];

void Update( int nod, int lf, int rg, int pos, int val )
{

    if( lf == rg )
    {
        tree[nod]=val;
        return;
    }

    int mid = lf+(rg-lf)/2;
    if(pos <= mid)
        Update(nod*2 ,lf , mid, pos, val );
    else Update(2*nod+1, mid+1, rg, pos, val);

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

}

int Query( int nod, int lf, int rg, int L, int R)
{
    if( L <=lf && rg<= R)
        return tree[nod];
    int mid = lf + (rg-lf)/2;

    int maxx = -2;

    if( L <= mid)
        maxx= max (maxx, Query( nod*2 , lf, mid, L, R));
    if( mid < R) maxx= max(maxx, Query(nod*2+1, mid+1, rg, L, R));

    return maxx;
}

void Read()
{
    int tip, a , b , x;

    fin>>N>>Q;

    for(int i=1 ;i<=N; ++i)
    {
        fin>>x;
        Update( 1, 1 , N, i, x );
    }
    for(int i=1; i<=Q; ++i)
    {
        fin>>tip>>a>>b;

        if(tip==0)
            fout<< Query ( 1, 1, N, a, b)<< "\n";
        else Update(1,1,N,a,b);


    }
}

int main()
{
    Read();
    return 0;
}