Program P1;
var i,n,m,k,sol,a,b : longword;
    max : array[0..299999] of longword;

Function maxim(a,b:longword):longword;
begin
    if a>b then maxim:=a
           else maxim:=b;
end;

Procedure creare(left,right,nod : longword);
var mijl:longword;
begin
    if left=right then read(max[nod])
                  else begin
                       mijl:=(left+right) div 2;
                       creare(left,mijl,2*nod);
                       creare(mijl+1,right,2*nod+1);
                       max[nod]:=maxim(max[2*nod],max[2*nod+1]);
                       end;
end;

Procedure caut_max(left,right,nod:longword);
var mijl:longword;
begin
    if (a<=left) and (b>=right) then begin
                                     if sol<max[nod] then sol:=max[nod];
                                     exit;
                                     end;
    mijl:=(left+right) div 2;
    if a<=mijl then caut_max(left,mijl,2*nod);
    if b>=mijl+1 then caut_max(mijl+1,right,2*nod+1);
end;

Procedure update(left,right,nod:longword);
var mijl:longword;
begin
    if left=right then max[nod]:=b
                  else begin
                       mijl:=(left+right) div 2;
                       if a<=mijl then update(left,mijl,2*nod)
                                  else update(mijl+1,right,2*nod+1);
                       max[nod]:=maxim(max[2*nod],max[2*nod+1]);
                       end;
end;

begin
    assign(input,'arbint.in'); reset(input);
    assign(output,'arbint.out'); rewrite(output);

    readln(n,m); creare(1,n,1);

    for i:=1 to m do begin
                     readln(k,a,b);
                     if k=0 then begin
                                 sol:=0;
                                 caut_max(1,n,1);
                                 writeln(sol);
                                 end
                             else update(1,n,1);
                     end;
end.