// arbori_intervale.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include<cstdio>

using namespace std;

#define nMax 300001

int N, M, A, B, Max;
int Arb[nMax];

inline int Maxim(int a, int b)
{
	if ( a > b )
		return a;
	return b;
}

void Actualizare(int vf, int st, int dr, int poz, int val)
{
	if ( st == dr )
	{
		Arb[vf] = val;
		return;
	}

	if ( poz <= (st+dr)/2 )
		Actualizare ( 2*vf, st, (st+dr)/2, poz, val );
	else
		Actualizare ( 2*vf+1, (st+dr)/2+1, dr, poz, val );

	Arb[vf] = Maxim ( Arb[2*vf], Arb[2*vf+1] );
}

void Interogare(int vf, int st, int dr, int S, int D)
{
	if ( S <= st && dr <= D && Max < Arb[vf] )
	{
		Max = Arb[vf];
		return;
	}

	if ( S <= (st+dr)/2 )
		Interogare ( 2*vf, st, (st+dr)/2, S, D );
	else
		Interogare ( 2*vf+1, (st+dr)/2+1, dr, S, D );
		
}

int _tmain(int argc, _TCHAR* argv[])
{
	freopen ( "arbint.in", "r", stdin );
	freopen ( "arbint.out", "w", stdout );

	scanf ( "%d %d", &N, &M );
	int w;
	for(int i=1; i<=N; i++)
	{
		scanf ( "%d", &w );
		Actualizare ( 1, 1, N, i, w );
	}

	for(int i=1; i<=M; i++)
	{
		scanf ( "%d %d %d", &w, &A, &B );

		if ( !w )
		{
			Max = -1;
			Interogare ( 1, 1, N, A, B );
			printf ( "%d\n", Max );
		}

		else
			Actualizare ( 1, 1, N, A, B );
	}

	fclose(stdin);
	fclose(stdout);

	return 0;
}