var t:array[1..1 shl 18] of longint;
    m,maxim,p,v,a,b:longint;
    fin,fout:text;
 function max(a,b:longint):longint;
 begin
 if a>b then max:=a else max:=b;
 end;

 procedure update(nod,l,r:longint);
 begin
 if l<r then
   if p<=(l+r) shr 1 then
  update(nod shl 1,l,(l+r) shr 1)
   else
    update((nod shl 1)+1,((l+r) shr 1)+1,r);
 if l=r then
   t[nod]:=v else t[nod]:=max(t[nod shl 1],t[(nod shl 1)+1]);
 end;

 procedure query(nod,l,r:longint);
 begin
  if (a<=l) and (r<=b) then
  begin
  if maxim<t[nod] then maxim:=t[nod];
  exit
  end
   else
    begin
   if a<=(l+r) shr 1 then query(nod shl 1,l,(l+r) shr 1);
   if (l+r) shr 1<b then query((nod shl 1)+1,((l+r) shr 1)+1,r);
   end;

 end;

 procedure citire;
 var n,m,i:longint;
     x,y,z:longint;
 begin
 assign(fin,'arbint.in');reset(fin);
 readln(fin,n,m);
 for i:=1 to n do
  begin
  read(fin,x);
  p:=i;v:=x;
  update(1,1,n);
  end;
 assign(fout,'arbint.out');rewrite(fout);
 for i:=1 to m do
  begin
  read(fin,x,y,z);
  if x=0 then
   begin
   a:=y;
   b:=z;maxim:=0;
   query(1,1,n);
   write(maxim,#10);
   end
   else
    begin
    p:=y;
    v:=z;
    update(1,1,n);
    end;
  end;
 close(fin);close(fout);
 end;

begin
citire;
end.