#include<cstdio>
using namespace std;

int max,arb[400005];

void modif(int nod,int st,int dr,int x,int y)
{
	int m;
	if(st==dr)
	{
		arb[nod]=y;
		return;
	}	
	m=(st+dr)/2;
	if(x<=m)
		modif(nod*2,st,m,x,y);
	else
		modif(nod*2+1,m+1,dr,x,y);
	if(arb[nod*2]>=arb[nod*2+1])
		arb[nod]=arb[nod*2];
	else
		arb[nod]=arb[nod*2+1];
}

void search(int nod,int st,int dr,int x,int y)
{
	int m;
	if(x<=st && dr<=y)
	{
		if(arb[nod]>max)
			max=arb[nod];
		return;
	}
	m=(st+dr)/2;
	if(x<=m)
		search(nod*2,st,m,x,y);
	if(m<y)
		search(nod*2+1,m+1,dr,x,y);
}

void rez()
{
	int i,m,n,x,a,b;
	freopen("arbint.in","r",stdin);
	freopen("arbint.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(i=1;i<=n;i++)
	{
		scanf("%d",&x);
		modif(1,1,n,i,x);
	}
	for(i=1;i<=m;i++)
	{
		scanf("%d%d%d",&x,&a,&b);
		if(x)
			modif(1,1,n,a,b);
		else
		{
			max=-1;
			search(1,1,n,a,b);
			printf("%d\n",max);
		}
	}
}

int main()
{
	rez();
	return 0;
}