// FMI - UNIBUC - INFO
/*
    _|_|_|_|  _|_|_|_|_|  _|_|     _|  _|_|_|_|  _|_|_|_|_|     _|       _|_|     _|  _|_|_|_|_|  _|  _|_|     _|
    _|        _|      _|  _| _|    _|  _|            _|       _| _|      _| _|    _|      _|      _|  _| _|    _|
    _|        _|      _|  _|  _|   _|  _|            _|      _|   _|     _|  _|   _|      _|      _|  _|  _|   _|
    _|        _|      _|  _|   _|  _|    _|_|_|      _|     _| _|_|_|    _|   _|  _|      _|      _|  _|   _|  _|
    _|        _|      _|  _|    _| _|        _|      _|    _|       _|   _|    _| _|      _|      _|  _|    _| _|
    _|_|_|_|  _|_|_|_|_|  _|     _|_|  _|_|_|_|      _|   _|         _|  _|     _|_|      _|      _|  _|     _|_|

*/
// Platform: Infoarena
// Problem: Arbori de intervale
// Programming Language: C++
// Date: 23.5.2016

# include <fstream>
# include <algorithm>
# include <vector>

using namespace std;

ifstream f ( "arbint.in" );
ofstream g ( "arbint.out" );

vector < int > A;

void update( int index, pair< int, int > seg, int poz, int val ) {

    if ( seg.first == seg.second ) {
        A[index] = val;
        return;
    }
    int mid = ( seg.first + seg.second ) / 2;
    if ( poz <= mid ) {
        update( index * 2, { seg.first, mid }, poz, val );
    }
    else {
        update( index * 2 + 1, { mid + 1, seg.second}, poz, val );
    }
    A[index] = max( A[index * 2], A[index * 2 + 1] );
}

int query( int index, pair< int, int > seg, pair< int, int > q ) {

    if ( q.first <= seg.first && seg.second <= q.second ) {
        return max( A[index], 0 );
    }
    int mid = ( seg.first + seg.second ) / 2;
    int answer = 0;
    if ( q.first <= mid ) {
        answer = max( answer, query( index * 2, { seg.first, mid }, q ) );
    }
    if ( q.second >= mid + 1 ) {
        answer = max( answer, query( index * 2 + 1, { mid + 1, seg.second }, q ) );
    }

    return answer;
}

int main()
{
    int n, m; f >> n >> m;
    A.resize( 4 * n, 0 );
    for ( int i = 1; i <= n; ++ i ) {
        int x; f >> x;
        update( 1, {1, n}, i, x );
    }
    for ( int i = 1; i <= m; ++ i ) {
        int op, a, b; f >> op >> a >> b;
        if ( op ) {
            update( 1, {1, n}, a, b );
        }
        else {
            g << query( 1, {1, n}, {a, b} ) << '\n';
        }
    }

    return 0;
}