#include<stdio.h>
long poz,val,i,n,m,a,b,max,mod;
long arb[4000000];

long maxim(long a,long b)
{
	if(a>b)
		return a;
	return b;
}
void refresh(long nod,long li,long ls)
{
long mij;
	if(li==ls)
		arb[nod]=val;
	else
	{
	mij=(li+ls)/2;
	if(poz<=mij)
		refresh(2*nod,li,mij);
	else
		refresh(2*nod+1,mij+1,ls);
	arb[nod]=maxim(arb[2*nod],arb[2*nod+1]);
	}
}
void ask(long nod,long li,long ls)
{
	long mij;
	if(a<=li&&b>=ls)
		{
		if(arb[nod]>max)
			max=arb[nod];}
	else
	{
	mij=(li+ls)/2;
	if(a<=mij)
		ask(2*nod,li,mij);
	if(b>mij)
		ask(2*nod+1,mij+1,ls);
	}
}
int main(void)
{
	freopen("arbint.in","r",stdin);
	freopen("arbint.out","w",stdout);
	scanf("%ld%ld",&n,&m);
	for(i=1;i<=n;i++)
	{
		scanf("%ld",&val);
		poz=i;
		refresh(1,1,n);
	}
	for(i=1;i<=n;i++)
	{
	scanf("%ld%ld%ld",&mod,&a,&b);
	if(!mod)
		{
		max=-1;
		ask(1,1,n);
		printf("%ld\n",max);
		}
	else
	{
		val=b;
		poz=a;
		refresh(1,1,n);
	}
	}
return 0;
}