program railway(input,output);
var
  c,s,r,o,d,n,i,j:longint;
  a:array[1..60001]of longint;
  k:boolean;
  f1,f2:text;
begin
  assign(f1,'railway.in');
  reset(f1);
  assign(f2,'railway.out');
  rewrite(f2);
  readln(f1,c,s,r);
  for i:=1 to c do
    a[i]:=s;
  for i:=1 to r do
  begin
    readln(f1,o,d,n);
    k:=true;
    for j:=o to d do
      if a[j]<n then k:=false;
    if k then
      begin
        writeln(f2,'YES');
        for j:=o to d do
          a[j]:=a[j]-n;
      end
      else writeln(f2,'NO');
  end;
  close(f1);
  close(f2);
end.