#include <cstdio> 
#include <cstdlib>

using namespace std ;

int nrFrunze , nrOperatii , arbore [ 400001 ] ;

void citireStart ( ) ;

void compunereArbore ( ) ;

void efectuareOperatie ( ) ;

void infundArbore ( int , int , int , int , int ) ;

int extragArbore ( int , int , int , int , int ) ;

inline int max ( int A , int B )
{
  return ( A > B ) ? A : B ;
}

int main ( )
{
  freopen ( "arbint.in", "r" , stdin ) ;
  freopen ( "arbint.out" , "w" , stdout ) ;
  citireStart ( ) ;
  compunereArbore ( ) ;
  for ( int i = 0 ; i < nrOperatii ; ++i )
    efectuareOperatie ( ) ;
}

void citireStart ( ) 
{
  scanf ("%d%d" , &nrFrunze , &nrOperatii ) ;
  return ;
}

void compunereArbore ( ) 
{
  int val ;
  for ( int i = 1 ; i <= nrFrunze ; ++i )
  {
    scanf ( "%d" , &val ) ;
    infundArbore ( i , val , 1 , nrFrunze , 1 ) ;
  }
  return ;
}

void efectuareOperatie ( ) 
{
  int opt ;
  int a , b ;
  scanf ( "%d%d%d" , &opt , &a , &b ) ;
  if ( opt )
    infundArbore ( a , b, 1, nrFrunze , 1 ) ;
  else
    printf ( "%d\n" , extragArbore ( a , max ( nrFrunze ,b ) , 1 , nrFrunze , 1 ) ) ;
  return ;
}

void infundArbore ( int Poz , int Val , int Stanga , int Dreapta , int Index )
{
  if ( Stanga == Dreapta )
  {
    arbore [ Index ] = Val ;
    return ;
  }
  if ( Poz > ( ( Stanga + Dreapta ) >> 1 ) )
  {
    infundArbore ( Poz , Val , ( ( Stanga + Dreapta ) >> 1 ) + 1 , Dreapta , ( Index << 1 ) + 1 ) ;
    arbore [ Index ] = max ( arbore [ Index << 1 ] , arbore [ ( Index << 1 ) + 1 ] ) ;
    return ;
  }
  else
  {
    infundArbore ( Poz , Val , Stanga , ( Stanga + Dreapta ) >> 1  , Index << 1 ) ;
    arbore [ Index ] = max ( arbore [ Index << 1 ] , arbore [ ( Index << 1 ) ] ) ;
    return ;
  }
}

int extragArbore ( int maxStanga , int maxDreapta , int Stanga , int Dreapta , int Index )
{
  if ( Stanga > maxDreapta || Dreapta < maxStanga ) 
    return 0 ;
  if ( Stanga >= maxStanga && Dreapta <= maxDreapta )
    return arbore [ Index ] ;
  return max ( extragArbore ( maxStanga , maxDreapta , ( ( Stanga + Dreapta ) >> 1 ) + 1 , Dreapta , ( Index << 1 ) + 1 ) ,
	       extragArbore ( maxStanga , maxDreapta , Stanga , ( Stanga + Dreapta ) >> 1 , Index << 1 ) );
}