/* 
 * File:   main.cpp
 * Author: VirtualDemon
 *
 * Created on April 6, 2010, 9:26 AM
 */
#include <cstdlib>
#include <fstream>
#define Nmax 400010

/*
 *
 */
using namespace std;
int Aint[Nmax];
inline const int& max( const int& x, const int& y )
{
    if( x > y )
        return x;
    return y;
}
inline void UpDate( int vertex, int left, int right, int P, int x )
{
    if( left == right )
    {
        Aint[vertex]=x;
        return;
    }
    int middle=left+(right-left)/2;
    if( P <= middle )
        UpDate( 2*vertex, left, middle, P, x );
    else UpDate( 2*vertex+1, middle+1, right, P, x );
    Aint[vertex]=max( Aint[2*vertex], Aint[2*vertex+1] );
}
inline int Query( int vertex, int left, int right, int a, int b )
{
    if( a <= left && right <= b )
        return Aint[vertex];
    int m=-1, middle=left+(right-left)/2;
    if( a <= middle )
        m=Query( 2*vertex, left, middle, a, b );
    if( b > middle )
        m=max( m, Query( 2*vertex+1, middle+1, right, a, b ) );
    return m;
}
int main( void )
{
    int N, M, i, j, k;
    ifstream in( "arbint.in" );
    ofstream out( "arbint.out" );
    in>>N>>M;
    for( i=1; i <= N; ++i )
    {
        in>>j;
        UpDate( 1, 1, N, i, j );
    }
    for( ; M; --M )
    {
        in>>i>>j>>k;
        if( 0 == i )
            out<<Query( 1, 1, N, j, k )<<'\n';
        else UpDate( 1, 1, N, j, k );
    }
    return EXIT_SUCCESS;
}