#include <stdio.h>
int arb[500105];
int max;
void mod(int nod,int p,int u,int x,int y)
{
int m;
if(u==p)
{
arb[nod]=y;
return ;
}
m=(p+u)/2;
if (x<=m)
mod(nod*2,p,m,x,y);
else
mod(nod*2+1,m+1,u,x,y);
if (arb[nod*2]>arb[nod*2+1])
arb[nod]=arb[nod*2];
else
arb[nod]=arb[nod*2+1];
}
void cauta(int nod,int p,int u, int x,int y)
{
int m;
if (x<=p&&u<=y)
{
if (arb[nod]>max)
max=arb[nod];
return;
}
m=(p+u)/2;
if (x<=m)
{
cauta(nod*2,p,m,x,y);
}
if (y>m)
{
cauta(nod*2+1,m+1,u,x,y);
}
}
int main()
{
FILE *in,*out;
int m,n,i,x,a,b;
in=fopen("arbint.in","r");
out=fopen("arbint.out","w");
fscanf(in,"%d%d",&m,&n);
for (i=1;i<=n;i++)
{
fscanf(in,"%d",&x);
mod(1,1,n,i,x);
}
for (i=1;i<=m;i++)
{
fscanf(in,"%d%d%d",&x,&a,&b);
if (x)
{
mod(1,1,n,a,b);
}
else
{
max=-1;
cauta(1,1,n,a,b);
fprintf(out,"%d\n",max);
}
}
fclose(in);
fclose(out);
return 0;
}