#include <cstdio>
#include<algorithm>
#define infile "arbint.in"
#define outfile "arbint.out"
#define INF 1<<30
#define n_max 100005
using namespace std;

int AI[2*n_max];

int N, M;


void update(int nod, int st, int dr, int poz, int x)
{
	if(st == dr)
	{
		AI[nod] = x;
		return;
	}
	
	int mij = st + (dr - st)/2;
	
	if(poz <= mij)
		update(2*nod, st, mij, poz, x);
	else
		update(2*nod+1, mij+1, dr, poz, x);

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


void query(int nod, int st, int dr, int a, int b, int &rez)
{
	if(a<=st && dr<=b)
	{
		rez = max(rez, AI[nod]);
		return;
	}
	
	int mij = st + (dr - st)/2;
	
	if(a <= mij)
		query(2*nod, st, mij, a, b, rez);
	if(mij < b)
		query(2*nod+1, mij+1, dr, a, b, rez);	
}



int main()
{
	freopen(infile, "r", stdin);
	freopen(outfile, "w", stdout);
	
	int Max, x, y, z;
	
	scanf("%d %d", &N, &M);

	for(int i=1;i<=N;i++)
	{
		scanf("%d",&x);
		
		update(1, 1, N, i, x);
	}
	
	while(M--)
	{
		scanf("%d %d %d", &x, &y, &z);
		
		if(!x)
		{
			query(1, 1, N, y, z, Max = -1);

            printf("%d\n", Max);
		}
		
		else
			update(1, 1, N, y, z);
	}
	
	fclose(stdin);
	fclose(stdout);

	return 0;
}