program happya;
const
  er:array[1..15]of longint=(2,4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768);
var
  a,left,right,ge:array[1..32768]of longint;
  i,j,k,l:longint;
  c:char;
  n,m:longint;
  o,p,q,r:longint;

procedure increase(x,y:longint);
var
  i,j:longint;
begin
  inc(a[x],y);
  j:=x;
  i:=x div 2;
  while i<>0 do
  begin
    if a[i]>=a[j] then break;
    a[i]:=a[j];
    ge[i]:=x;
    j:=i;
    i:=i div 2;
  end;
end;

procedure find(x:longint);
begin
  if (left[x]>=o)and(right[x]<=p) then
  begin
    if a[x]>r then
    begin
      r:=a[x];
      q:=ge[x];
    end;
  end
  else
  begin
    if o<=right[x*2] then
      find(x*2);
    if p>=left[x*2+1] then
      find(x*2+1);
  end;
end;

function max(x,y:longint):longint;
begin
  if x>y then exit(x)
  else exit(y);
end;

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

  readln(n,m);

  for i:=1 to 15 do
    if er[i]>n then break;
  k:=i;
  for i:=er[k] to er[k+1]-1 do
  begin
    a[i]:=0;
    left[i]:=i-er[k]+1;
    right[i]:=left[i];
    ge[i]:=i;
  end;
  for i:=er[k]-1 downto 1 do
  begin
    a[i]:=0;
    left[i]:=left[2*i];
    right[i]:=right[2*i+1];
    ge[i]:=0;
  end;

  for l:=1 to m do
  begin
    read(c);
    case c of
      'I':
      begin
        readln(o,p,q);
        for i:=o to p do
          increase(er[k]+i-1,q);
      end;
      'C':
      begin
        readln(o,p);
        r:=0;
        q:=0;
        find(1);
        writeln(r);
        a[q]:=0;
        i:=q div 2;
        j:=q;
        while i<>0 do
        begin
          r:=max(a[i*2],a[i*2+1]);
          if r=a[i] then break;
          a[i]:=r;
          r:=i*2;
          if r=j then
            ge[i]:=ge[r+1]
          else
            ge[i]:=ge[r];
          j:=i;
          i:=i div 2;
        end;
      end;
    end;
  end;

  close(input);
  close(output);
end.